eMedicine Specialties > Pulmonology > Infectious Lung Diseases

Pneumonia, Bacterial: Treatment & Medication

Author: Nader Kamangar, MD, FACP, FCCP, FAASM, Associate Professor of Clinical Medicine, Division of Pulmonary, Critical Care and Sleep Medicine, Multi-campus Pulmonary and Critical Care Fellowship Program, University of California, Los Angeles, David Geffen School of Medicine; Medical Director, Hospitalist/Intensivist Program, Olive View-UCLA Medical Center; Associate Program Director, Combined Pulmonary and Critical Care Fellowship Program, Cedars-Sinai/Olive View-UCLA Medical Center/West Los Angeles Veterans Affairs Medical Center
Coauthor(s): Christina Rager, MD, Resident Physician, Internal and Emergency Medicine, Olive View-University of California at Los Angeles Medical Center; Sat Sharma, MD, FRCPC, Professor and Head, Division of Pulmonary Medicine, Department of Internal Medicine, University of Manitoba; Site Director, Respiratory Medicine, St Boniface General Hospital
Contributor Information and Disclosures

Updated: Aug 21, 2009

Treatment

Medical Care

The information in this section is derived mainly from the current Infectious Diseases Society of America/American Thoracic Society (IDSA/ATS) guidelines for the management of community-acquired pneumonia (CAP).10
 
Almost all major decisions regarding management of pneumonia address the initial assessment of severity. Perhaps the most important initial determination is that of the need for hospitalization.

In determining site or level of care, options include outpatient, medical ward care, or medical ICU care.

Risk stratification

Severity-of-illness scores or prognostic models, such as the CURB-65 criteria or the Pneumonia Severity Index (PSI) can be used to help identify patients that may be candidates for outpatient treatment and those that may require admission.

CURB-65

CURB-65 is a scoring system developed from a multivariate analysis of 1068 patients that identified various factors that appeared to play a role in patient mortality.25 One point is given for the presence of each of the following:

  • Confusion
  • Uremia - BUN greater than 20 mg/dL
  • Respiratory rate of greater than or equal to 30 breaths per minute
  • Blood pressure - Systolic less than 90 mm Hg or diastolic less than 60 mm Hg
  • Age older than 65 years

Current guidelines suggest that patients may be treated in an outpatient setting or may require hospitalization according to their CURB-65 score, as follows:

  • Score of 0-1 - Outpatient treatment
  • Score of 2 - Admission to medical ward
  • Score of 3 or higher - Admission to ICU

The percent mortality at 30 days associated with the various CURB-65 scores is below; the drastic increase in mortality between scores of 2 and 3 highlights the likely requirement for ICU admission in patients with a score of 3 or higher.

  • Score of 0 - 0.7%
  • Score of 1 - 2.1%
  • Score of 2 - 9.2%
  • Score of 3 - 14.5%
  • Score of 4 - 40%
  • Score of 5 - 57%

Pneumonia Severity Index

The PSI is based on the derivation of a prediction rule for mortality and its validation based on characteristics of cohorts of hospitalized patients.31 For each of the various characteristics, a predetermined value of points assigned, as follows:

  • Demographic factors
    • Age, men - Age in years
    • Age, women - Age in years minus 10 points
    • Nursing home resident - Add 10 points
  • Coexisting illnesses
    • Neoplasia - Add 30 points
    • Liver disease - Add 20 points
    • Congestive heart failure - Add 10 points
    • Cerebrovascular disease - Add 10 points
    • Renal disease - Add 10 points
  • Physical examination findings
    • Altered mental status - Add 20 points
    • Respiratory rate greater than or equal to 30 breaths per minute - Add 20 points
    • Systolic blood pressure lower than 90 mm Hg - Add 20 points
    • Temperature lower than 35°C or greater than or equal to 40°C - Add 15 points
    • Pulse greater than or equal to 125 bpm - Add 10 points
  • Laboratory and radiographic findings
    • Arterial pH less than 7.35 - Add 30 points
    • BUN greater than or equal to 30 mg/dL - Add 20 points
    • Sodium level less than 130 mmol/L - Add 20 points
    • Glucose level greater than or equal to 250 mg/dL - Add 10 points
    • Hematocrit value less than 30% - Add 10 points
    • PaO2 less than 60 mm Hg or oxygen saturation (SpO2) less than 90% - Add 10 points
    • Pleural effusion - Add 10 points

The total points added together make up the risk score, which stratifies patients into 5 mortality risk classes:

  • Class I is 0-50 points - 0.1% mortality
  • Class II is 51-70 points - 0.6% mortality
  • Class III is 71-90 points - 0.9% mortality
  • Class IV is 91-130 points - 9.3% mortality
  • Class V is greater than 130 points - 27% mortality

Current guidelines suggest that patients may be treated in an outpatient setting or may require hospitalization depending on their risk class, as follows:

  • Classes I and II - Outpatient management
  • Class III - Admission to an observation unit or for short hospital stay
  • Classes IV and V - Treatment in inpatient setting

Importantly, remember that objective criteria and scores should be used as guides only and should always be supplemented with physician determination of the patient's therapeutic needs. The risks and benefits of hospitalization should be weighed carefully because hospitalization can put patients at additional risk (eg, thromboembolic events, nosocomial superinfection).

Severe CAP

Additional criteria that can help determine the need for ICU admission are the presence of 3 minor criteria that compose the definition of severe CAP.

Minor criteria are as follows:

  • Respiratory rate greater than or equal to 30 breaths per minute
  • Ratio of PaO2 to fraction of inspired oxygen (ie, PaO2/FiO 2 ) of less than or equal to 250
  • Need for noninvasive ventilation (bilevel positive airway pressure [BiPAP] or continuous positive airway pressure [CPAP])
  • Multilobar infiltrates
  • Confusion/disorientation
  • Uremia (BUN greater than or equal to 20 mg/dL)
  • Leukopenia (WBC count <4000 cells/µL)
  • Thrombocytopenia (platelet count <100,000/µL)
  • Hypothermia (core temperature <36°C)
  • Hypotension requiring aggressive fluid resuscitation
Major criteria are as follows:
  • Invasive mechanical ventilation
  • Septic shock requiring vasopressor support
Direct admission to an ICU is mandated for any patient in septic shock with a requirement for vasopressors or with acute respiratory failure requiring intubation and mechanical ventilation.

Consultations

Consultation with infectious disease and/or pulmonary specialists is suggested in difficult cases.

  • Patients requiring noninvasive mechanical ventilation or intubation may need consultation with a critical care medicine specialist to aid in management after admission to the ICU.
  • A pharmacist and/or infection control specialist may be of assistance in providing information on hospital or regional bacterial resistance and sensitivity patterns.

Medication

The goals of pharmacotherapy for bacteria pneumonia are to eradicate the infection, reduce morbidity, and prevent complications.

Treatment of pneumonia depends largely on the empiric use of antibiotic regimens directed against potential pathogens as determined by the setting in which the infection took place (ie, community-acquired pneumonia [CAP], health care–associated pneumonia [HCAP], hospital-acquired pneumonia [HAP], ventilator-associated pneumonia [VAP]). Discussion of empiric antibiotic therapy can be based on hospitalization status.

Outpatient empiric antibiotic therapy
 
Antibiotic choices in the outpatient setting should be driven by the presence of patient risk factors, including recent exposure to antibiotics, comorbidities, and local trends in antibiotic resistance10 :

In previously healthy patients with no exposure to antibiotics within the previous 90 days, use the following: 

  • Macrolide or doxycycline (weak recommendation)

In patients with comorbidities such as chronic disease of the heart, lung, liver, or kidneys; diabetes mellitus; alcoholism; malignancy; immunosuppression (drug- or disease-induced); or use of antimicrobials within the last 90 days, use the following:

  • Respiratory fluoroquinolone or beta-lactam plus macrolide

If the patient was exposed to antibiotics within the previous 90 days for systemic treatment of any type of bacterial infection, an alternative from a different class should be selected for treatment of the current illness.

Inpatient empiric antibiotic therapy
 
Inpatient treatment of pneumonia, according to 2009 Joint Commission and the Centers for Medicare and Medicaid Services consensus guidelines, should be given within 6 hours of hospital admission (or in the emergency department if this is where the patient initially presented) and should consist of the following antibiotic regimens32 :

  • Non-ICU patients (choice of one option)
    • Beta-lactam (IV or IM) plus macrolide (IV or PO)
    • Antipneumococcal quinolone monotherapy (IV or IM) 
    • Beta-lactam (IV or IM) plus doxycycline (IV or oral)
    • If patient younger than 65 years with no risk factors for drug-resistant pneumococcus - Macrolide monotherapy (IV or oral)
  • ICU Patients (choice of one option)
    • Beta-lactam (IV) plus macrolide (IV)
    • Beta-lactam (IV) plus antipneumococcal quinolone (IV)
    • If patient has documented beta-lactam allergy - Antipneumococcal quinolone (IV) plus aztreonam (IV)
  • Patients at increased risk of infection with Pseudomonas (acceptable for both ICU and non-ICU patients) (choice of one option)
    • Antipseudomonal beta-lactam (IV) plus antipseudomonal quinolone (IV; PO in non-ICU only)
    • Antipseudomonal beta-lactam (IV) plus aminoglycoside (IV) plus one of the following:
      • Macrolide (IV)
      • Antipneumococcal quinolone (IV; PO in non-ICU only)
      • If patient has documented beta-lactam allergy - Aztreonam (IV) plus aminoglycoside (IV) plus antipneumococcal quinolone (IV; PO in non-ICU only)

A note on antibiotics in HAP and VAP
 
The prevalence and resistance patterns of multidrug-resistant (MDR) pathogens vary between institutions and even between ICUs within the same institution; therefore, appropriate initial antibiotic therapy for HAP and VAP may vary markedly according to hospital site. Antimicrobial prescribing practices should not necessarily be based on national guidelines, but rather on patterns of MDR organisms at individual institutions.6

A note on MRSA
 
For suspected infection with methicillin-resistant S aureus (MRSA), vancomycin or linezolid may be added to the antibiotic regimen until the organism's identity and antibiotic sensitivities are known, at which point the medications can be adjusted accordingly. Neither vancomycin nor linezolid is an optimal agent for treatment of methicillin-sensitive S aureus (MSSA).10 Other agents that may be considered for use against MRSA include clindamycin, trimethoprim- sulfamethoxazole (TMP-SMZ), gentamicin, ciprofloxacin, and rifampin; still other antibiotics are being evaluated for activity against MRSA.33

Aspiration pneumonia empiric therapy
 
Although the causative organisms in aspiration pneumonia have been noted to be similar to those of CAP or HCAP, patients with severe periodontal disease, putrid sputum, or a history of alcoholism with suspected aspiration pneumonia may be at greater risk of anaerobic infection. One of the following antibiotic regimens is suggested for such patients8,10 :

  • Piperacillin-tazobactam
  • Imipenem
  • Clindamycin or metronidazole plus a respiratory fluoroquinolone plus ceftriaxone

Pathogen-driven antibiotic choices10

Open table in new window

Table
OrganismFirst-Line AntimicrobialsAlternative Antimicrobials
Streptococcus pneumoniae  
Penicillin nonresistant (MIC* <2 mcg/mLPenicillin G, amoxicillinMacrolide, cephalosporins (oral or parenteral), clindamycin, doxycycline, respiratory fluoroquinolone
Penicillin resistant (MIC ≥2 mcg/mLAgents chosen on the basis of sensitivityVancomycin, linezolid, high-dose amoxicillin (3 g/d with MIC ≤4 mcg/mL
Staphylococcus aureus  
Methicillin susceptibleAntistaphylococcal penicillinCefazolin, clindamycin
Methicillin resistantVancomycin, linezolidTrimethoprim- sulfamethoxazole
Haemophilus influenzae  
Nonbeta-lactamase producingAmoxicillinFluoroquinolone, doxycycline, azithromycin, clarithromycin
Beta-lactamase producingSecond- or third-generation cephalosporin, amoxicillin/clavulanateFluoroquinolone, doxycycline, azithromycin, clarithromycin
Mycoplasma pneumoniaeMacrolide, a tetracyclineFluoroquinolone
Chlamydophila pneumoniaeMacrolide, a tetracyclineFluoroquinolone
Legionella speciesFluoroquinolone, azithromycinDoxycycline
Chlamydophila psittaciA tetracyclineMacrolide
Coxiella burnetiiA tetracyclineMacrolide
Francisella tularensisDoxycyclineGentamicin, streptomycin
Yersinia pestisStreptomycin, gentamicinDoxycycline, fluoroquinolone
Bacillus anthracis (inhalational)Ciprofloxacin, levofloxacin, doxycyclineOther fluoroquinolones, beta-lactam (if susceptible), rifampin, clindamycin, chloramphenicol
EnterobacteriaceaeThird-generation cephalosporin, carbapenemBeta-lactam/beta-lactamase inhibitor, fluoroquinolone
Pseudomonas aeruginosaAntipseudomonal beta-lactam plus ciprofloxacin, levofloxacin, or aminoglycosideAminoglycoside plus ciprofloxacin or levofloxacin
Bordetella pertussisMacrolideTrimethoprim- sulfamethoxazole
Anaerobe (aspiration)Beta-lactam/beta-lactamase inhibitor, clindamycinCarbapenem
OrganismFirst-Line AntimicrobialsAlternative Antimicrobials
Streptococcus pneumoniae  
Penicillin nonresistant (MIC* <2 mcg/mLPenicillin G, amoxicillinMacrolide, cephalosporins (oral or parenteral), clindamycin, doxycycline, respiratory fluoroquinolone
Penicillin resistant (MIC ≥2 mcg/mLAgents chosen on the basis of sensitivityVancomycin, linezolid, high-dose amoxicillin (3 g/d with MIC ≤4 mcg/mL
Staphylococcus aureus  
Methicillin susceptibleAntistaphylococcal penicillinCefazolin, clindamycin
Methicillin resistantVancomycin, linezolidTrimethoprim- sulfamethoxazole
Haemophilus influenzae  
Nonbeta-lactamase producingAmoxicillinFluoroquinolone, doxycycline, azithromycin, clarithromycin
Beta-lactamase producingSecond- or third-generation cephalosporin, amoxicillin/clavulanateFluoroquinolone, doxycycline, azithromycin, clarithromycin
Mycoplasma pneumoniaeMacrolide, a tetracyclineFluoroquinolone
Chlamydophila pneumoniaeMacrolide, a tetracyclineFluoroquinolone
Legionella speciesFluoroquinolone, azithromycinDoxycycline
Chlamydophila psittaciA tetracyclineMacrolide
Coxiella burnetiiA tetracyclineMacrolide
Francisella tularensisDoxycyclineGentamicin, streptomycin
Yersinia pestisStreptomycin, gentamicinDoxycycline, fluoroquinolone
Bacillus anthracis (inhalational)Ciprofloxacin, levofloxacin, doxycyclineOther fluoroquinolones, beta-lactam (if susceptible), rifampin, clindamycin, chloramphenicol
EnterobacteriaceaeThird-generation cephalosporin, carbapenemBeta-lactam/beta-lactamase inhibitor, fluoroquinolone
Pseudomonas aeruginosaAntipseudomonal beta-lactam plus ciprofloxacin, levofloxacin, or aminoglycosideAminoglycoside plus ciprofloxacin or levofloxacin
Bordetella pertussisMacrolideTrimethoprim- sulfamethoxazole
Anaerobe (aspiration)Beta-lactam/beta-lactamase inhibitor, clindamycinCarbapenem

*MIC - Minimal inhibitory concentration.

Other medications

Corticosteroids

The role of supplementing corticosteroids in patients with hypotension from septic shock remains controversial; however, screening for occult adrenal insufficiency is recommended in hypotensive, fluid-resuscitated patients with severe CAP.

Drotrecogin alfa 

A recombinant version of human activated protein C, drotrecogin alfa is the first immunomodulatory drug approved for the treatment of severe sepsis. It is recommended in patients with CAP who have persistent septic shock despite adequate fluid resuscitation. Its use is recommended in patients at high risk of death.

Antibiotic, Penicillin


Amoxicillin (Amoxil, Biomox, Trimox)

Derivative of ampicillin and has similar antibacterial spectrum, namely certain gram-positive and gram-negative organisms. Superior bioavailability and stability to gastric acid and has broader spectrum of activity than penicillin. Somewhat less active than that of penicillin against S pneumococcus. Penicillin-resistant strains also resistant to amoxicillin, but higher doses may be effective. More effective against gram-negative organisms (eg, N meningitidis, H influenzae) than penicillin. Interferes with synthesis of cell wall mucopeptides during active multiplication, resulting in bactericidal activity against susceptible bacteria.

Adult

250-500 mg PO q8h; not to exceed 3 g/d

Pediatric

20-50 mg/kg/d PO divided q8h; not to exceed 2 g/dose

Reduces the efficacy of oral contraceptives

Pregnancy

B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals

Precautions

Adjust dose in renal impairment; may enhance chance of candidiasis


Ampicillin (Principen)

Broad-spectrum penicillin. Interferes with bacterial cell wall synthesis during active replication, causing bactericidal activity against susceptible organisms. Alternative to amoxicillin when unable to take medication orally.
HACEK bacteria previously were uniformly susceptible to ampicillin; however, beta-lactamase–producing strains of HACEK have been identified.

Adult

250-500 mg PO q6h
500 mg to 1.5 g IM q4-6h
500 mg to 3 g IV q4-6h; not to exceed 12 g/d

Pediatric

50-100 mg/kg/d PO divided q4-6h
100-400 mg/kg/d IM/IV divided q4-6h

Probenecid and disulfiram elevate ampicillin levels; allopurinol decreases ampicillin effects and has additive effects on ampicillin rash; may decrease effects of oral contraceptives

Pregnancy

B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals

Precautions

Adjust dose in renal failure; evaluate rash and differentiate from hypersensitivity reaction


Penicillin G (Pfizerpen)

Interferes with synthesis of cell wall mucopeptide during active multiplication, resulting in bactericidal activity against susceptible microorganisms.

Adult

2.4 million U IM (single dose) in 2 injection sites

Pediatric

50,000 U/kg IM; not to exceed 2.4 million U

Probenecid can increase effects of penicillin; coadministration of tetracyclines can decrease effects of penicillin

Pregnancy

B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals

Precautions

Caution in impaired renal function


Piperacillin and tazobactam sodium (Zosyn)

Antipseudomonal penicillin plus beta-lactamase inhibitor. Inhibits biosynthesis of cell wall mucopeptide and is effective during stage of active multiplication.

Adult

3.375 g (piperacillin 3 g and tazobactam 0.375 g) IV q6h

Pediatric

<12 years: Not established
>12 years: Administer as in adults

Tetracyclines may decrease effects of piperacillin; high concentrations of piperacillin may physically inactivate aminoglycosides if administered in same IV line; effects when administered concurrently with aminoglycosides are synergistic; probenecid may increase penicillin levels; high dose parenteral penicillins may result in increased risk of bleeding

Documented hypersensitivity; severe pneumonia, bacteremia, pericarditis, emphysema, meningitis and purulent or septic arthritis should not be treated with an oral penicillin during the acute stage

Pregnancy

B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals

Precautions

Perform CBC counts prior to initiation of therapy and at least weekly during therapy; monitor for liver function abnormalities by measuring AST and ALT levels during therapy; exercise caution in patients diagnosed with hepatic insufficiencies; perform urinalysis, and BUN and creatinine determinations during therapy and adjust dose if values become elevated; monitor blood levels to avoid possible neurotoxic reactions

Antibiotic, Penicillin & Beta-Lactamase Inhibitor


Amoxicillin and clavulanate (Augmentin, Augmentin XR)

Amoxicillin inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins. Addition of clavulanate inhibits beta-lactamase producing bacteria.
Good alternative antibiotic for patients allergic or intolerant to the macrolide class. Usually is well tolerated and provides good coverage to most infectious agents. Not effective against Mycoplasma and Legionella species. Half-life of oral dosage form is 1-1.3 h. Has good tissue penetration but does not enter cerebrospinal fluid.
For children >3 mo, base dosing protocol on amoxicillin content. Due to different amoxicillin/clavulanic acid ratios in 250-mg tab (250/125) vs 250 mg chewable-tab (250/62.5), do not use 250-mg tab until child weighs >40 kg.

Adult

500-875 mg PO q12h or 250-500 mg PO q8h for 7-10 d

Pediatric

<3 months: 125 mg/5 mL PO susp; 30 mg/kg/d (based on amoxicillin component) divided bid for 7-10 d
>3 months: if using 200 mg/5 mL or 400 mg/5 mL susp, 45 mg/kg/d PO divided q12h; if using 125 mg/5 mL or 250 mg/5 mL suspension, 40 mg/kg/d PO divided bid for 7-10 d
>40 kg: Administer as in adults

Coadministration with warfarin or heparin, increases risk of bleeding; may act synergistically against selected microorganisms when coadministered with aminoglycosides; coadministration with allopurinol may increase incidence of amoxicillin rash; may decrease efficacy of oral contraceptives when administered concomitantly

Pregnancy

B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals

Precautions

Hepatic impairment may occur with prolonged treatment in the elderly; diarrhea may occur; adjust dose in renal impairment; cross allergy may occur with other beta-lactams and cephalosporins


Ampicillin and sulbactam (Unasyn)

Drug combination of beta-lactamase inhibitor with ampicillin. Interferes with bacterial cell wall synthesis during active replication, causing bactericidal activity against susceptible organisms. Alternative to amoxicillin when unable to take medication orally.
Covers skin, enteric flora, and anaerobes. Not ideal for nosocomial pathogens.

Adult

1.5 (1 g ampicillin + 0.5 g sulbactam) to 3 g (2 g ampicillin + 1 g sulbactam) IV/IM q 6-8h; not to exceed 4 g/d sulbactam or 8 g/d ampicillin

Pediatric

<3 months: Not established
3 months to 12 years: 100-200 mg ampicillin/kg/d (150-300 mg Unasyn) IV divided q6h
>12-years: Administer as in adults; not to exceed 4 g/d sulbactam or 8 g/d ampicillin

Probenecid and disulfiram elevate ampicillin levels; allopurinol decreases ampicillin effects and has additive effects on ampicillin rash; may decrease effects of oral contraceptives

Pregnancy

B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals

Precautions

Adjust dose in renal failure; evaluate rash and differentiate from hypersensitivity reaction

Antibiotic, Macrolide


Azithromycin (Zithromax)

Acts by binding to 50S ribosomal subunit of susceptible microorganisms and blocks dissociation of peptidyl tRNA from ribosomes, causing RNA-dependent protein synthesis to arrest. Nucleic acid synthesis is not affected.
Concentrates in phagocytes and fibroblasts as demonstrated by in vitro incubation techniques. In vivo studies suggest that concentration in phagocytes may contribute to drug distribution to inflamed tissues.
Treats mild-to-moderate microbial infections.

Adult

Day 1: 500 mg PO
Days 2-5: 250 mg PO qd
Alternatively, 1 g PO once

Pediatric

<6 months: Not established
>6 months:
Day 1: 10 mg/kg PO once; not to exceed 500 mg/d
Days 2-5: 5 mg/kg PO qd; not to exceed 250 mg/d

May increase toxicity of theophylline, warfarin, and digoxin; effects are reduced with coadministration of aluminum and/or magnesium antacids; nephrotoxicity and neurotoxicity may occur when coadministered with cyclosporine

Documented hypersensitivity; hepatic impairment; do not administer with pimozide

Pregnancy

B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals

Precautions

Site reactions can occur with IV route; bacterial or fungal overgrowth may result from prolonged antibiotic use; may increase hepatic enzymes and cholestatic jaundice; caution in patients with impaired hepatic function or prolonged QT intervals


Clarithromycin (Biaxin)

Semisynthetic macrolide antibiotic that reversibly binds to P site of 50S ribosomal subunit of susceptible organisms and may inhibit RNA-dependent protein synthesis by stimulating dissociation of peptidyl t-RNA from ribosomes, causing bacterial growth inhibition.
Used to treat CAP caused by H influenzae, M pneumoniae, S pneumoniae, M catarrhalis, H parainfluenzae, or C pneumoniae (TWAR strain).

Adult

250 mg PO bid for 7-14 d; alternatively, 1 g PO qd pc of extended-release product for 7 d

Pediatric

7.5 mg/kg PO bid; not to exceed 500 mg/d

Toxicity increases with coadministration of fluconazole and pimozide; effects decrease and adverse GI effects may increase with coadministration of rifabutin or rifampin; may increase toxicity of anticoagulants, cyclosporine, tacrolimus, digoxin, carbamazepine, ergot alkaloids, triazolam, HMG-CoA reductase inhibitors
Plasma levels of certain benzodiazepines may increase, prolonging CNS depression; arrhythmias and increases in QTc intervals occur with disopyramide; coadministration with omeprazole may increase plasma levels of both agents; decreases metabolism of repaglinide, thus increasing serum levels and effects

Documented hypersensitivity; coadministration of pimozide

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Coadministration with ranitidine or bismuth citrate is not recommended with CrCl <25 mL/min; give half dose or increase dosing interval if CrCl <30 mL/min; diarrhea may be sign of pseudomembranous colitis; superinfections may occur with prolonged or repeated antibiotic therapies


Erythromycin (E.E.S., E-Mycin, Eryc, Ery-Tab, Erythrocin)

Inhibits bacterial growth, possibly by blocking dissociation of peptidyl t-RNA from ribosomes, causing RNA-dependent protein synthesis to arrest. May result in GI upset, causing some to prescribe an alternative macrolide or change to tid dosing. Covers most potential etiologic agents, including Mycoplasma species. PO regimen may be insufficient to adequately treat Legionella species. Erythromycin is less active against H influenzae. Although standard course of treatment seems to be 10 d, treating until patient has been afebrile for 3-5 d seems to be a more rational approach.

Adult

250 mg erythromycin stearate/base (or 400 mg ethylsuccinate) PO q6h, or 500 mg q12h (1 h ac or 2 h pc)
Alternatively, 333 mg PO q8h; increase to 4 g/d depending on severity of infection
Hospitalized patients with severe pneumonia: 1 g IV q6h; alternatively, 15-20 mg/kg/d IV in divided doses q6h

Pediatric

7.5 mg/kg/d PO divided bid; alternatively, 20-40 mg/kg/d IV divided q6h or by constant infusion; not to exceed 4 g/d

Inhibits CYP450 1A2, 3A3/4 isoenzymes; coadministration may increase toxicity of theophylline, digoxin, carbamazepine, and cyclosporine; may potentiate anticoagulant effects of warfarin; coadministration with lovastatin and simvastatin increases risk of rhabdomyolysis; decreases metabolism of repaglinide, thus increasing serum levels and effects

Documented hypersensitivity; hepatic impairment

Pregnancy

B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals

Precautions

Caution in liver disease; estolate formulation may cause cholestatic jaundice; adverse GI effects are common (give doses pc); discontinue use if nausea, vomiting, malaise, abdominal colic, or fever occur

Antibiotic, Miscellaneous


Aztreonam (Azactam)

A monobactam, not a beta-lactam, antibiotic that inhibits cell wall synthesis during bacterial growth. Active against gram-negative bacilli but very limited gram-positive activity and not useful for anaerobes. Lacks cross-sensitivity with beta-lactam antibiotics. May be used in patients allergic to penicillins or cephalosporins.
Duration of therapy depends on severity of infection and continued for at least 48 h after patient asymptomatic or evidence of bacterial eradication obtained. Doses smaller than indicated should not be used.
Transient or persistent renal insufficiency may prolong serum levels. After initial loading dose of 1 or 2 g, reduce dose by half for estimated CrCl of 10-30 mL/min/1.73 m2. When only serum creatinine concentration available, the following formula (based on sex, weight, and age) can approximate CrCl. Serum creatinine should represent a steady state of renal function.
Males: CrCl = [(weight in kg)(140 - age)] divided by (72 X serum creatinine in mg/dL)
Females: 0.85 X above value
In patients with severe renal failure (CrCl <10 mL/min/1.73 m2), those supported by hemodialysis (HD), usual dose of 500 mg, 1 g, or 2 g, is given initially.
Maintenance dose is one fourth of usual initial dose given at usual fixed interval of 6, 8, or 12 h.
For serious or life-threatening infections, supplement maintenance doses with one eighth of initial dose after each HD session.
Elderly persons may have diminished renal function. Renal status is a major determinant of dosage in these patients. Serum creatinine may not be an accurate determinant of renal status. Therefore, as with all antibiotics eliminated by kidneys, obtain estimates of CrCl and make appropriate dosage modifications. Data insufficient regarding IM administration to pediatric patients or dosing in pediatric patients with renal impairment. Administered IV only to pediatric patients with normal renal function.

Adult

500-1000 g IV/IM q8-12h

Pediatric

90-120 mg/kg/d IV/IM divided q6-8h

Tetracyclines may reduce effects

Pregnancy

B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals

Precautions

Adjust dose in renal insufficiency


Clindamycin (Cleocin)

Semisynthetic antibiotic produced by 7(S)-chloro-substitution of 7(R)-hydroxyl group of parent compound lincomycin. Inhibits bacterial growth, possibly by blocking dissociation of peptidyl tRNA from ribosomes, causing RNA-dependent protein synthesis to arrest. Widely distributes in the body without penetration of CNS. Protein bound and excreted by liver and kidneys.
Available in parenteral form (ie, clindamycin phosphate) and oral form (ie, clindamycin hydrochloride). Oral clindamycin is absorbed rapidly and almost completely and is not appreciably altered by presence of food in stomach. Appropriate serum levels reached and sustained for at least 6 h following oral dose. No significant levels attained in cerebrospinal fluid. Also effective against aerobic and anaerobic streptococci (except enterococci).

Adult

600 mg IV q8h; continue treatment with 300 mg PO q6h; doses as high as 4800 mg qd have been used in life-threatening severe infections

Pediatric

8-20 mg/kg/d PO as hydrochloride and 8-25 mg/kg/d as palmitate divided tid/qid
20-40 mg/kg/d IV/IM equally divided tid/qid
Use the higher dose for more severe infections

Increases duration of neuromuscular blockade induced by tubocurarine and pancuronium; erythromycin may antagonize effects; antidiarrheals may delay absorption

Documented hypersensitivity; regional enteritis, ulcerative colitis, hepatic impairment, antibiotic-associated colitis

Pregnancy

B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals

Precautions

Adjust dose in severe hepatic dysfunction; no adjustment necessary in renal insufficiency; associated with severe and possibly fatal colitis by allowing overgrowth of Clostridium difficile


Vancomycin (Vancocin)

Classified as glycopeptide agent that has excellent gram-positive coverage, including MRSA. To avoid toxicity, current recommendation is to assay trough levels after third dose drawn 0.5 h prior to next dosing. Use CrCl to adjust dose in patients diagnosed with renal impairment.

Adult

500 mg IV q6h or 1 g IV q12h; not to exceed 10 mg/min

Pediatric

40 mg/kg/d IV divided tid/qid

Erythema, histaminelike flushing and anaphylactic reactions may occur when administered with anesthetic agents; taken concurrently with aminoglycosides, risk of nephrotoxicity may increase above that with aminoglycoside monotherapy; effects in neuromuscular blockade may be enhanced when coadministered with nondepolarizing muscle relaxants

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Caution in renal failure and neutropenia; red man syndrome is caused by too rapid IV infusion (dose given over a few min) but rarely happens when dose given IV over 2 h or PO or IP; red man syndrome is not an allergic reaction

Antibiotic, Cephalosporin (Fourth Generation)


Cefepime (Maxipime)

Fourth-generation cephalosporin. Gram-negative coverage comparable to ceftazidime but has better gram-positive coverage (comparable to ceftriaxone). Cefepime is a zwitter ion; rapidly penetrates gram-negative cells. Best beta-lactam for IM administration. Poor capacity to cross blood-brain barrier precludes use for treatment of meningitis.

Adult

1-2 g IV q12h for 5-10 d; pseudomonal infections require higher doses

Pediatric

50 mg/kg IV q8h; not to exceed 2 g

Probenecid may increase effects; aminoglycosides increase nephrotoxic potential of cefepime

Pregnancy

B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals

Precautions

Dosage adjustments (adult adjustments)
CrCl (mL/min) 80-50: 0.5-2 g q12-24h
CrCl 50-10: 0.5-2 g/d
CrCl <10: 0.25-0.5 g/d
HD: as for CrCl <10, with an extra 0.25 g after HD
During peritoneal dialysis: 1-2 g q48h
High doses may cause CNS toxicity; prolonged use may predispose patients to superinfection

Antibiotic, Cephalosporin (Third Generation)


Cefotaxime (Claforan)

Third-generation cephalosporin with broad gram-negative spectrum, lower efficacy against gram-positive organisms, and higher efficacy against resistant organisms. Arrests bacterial cell wall synthesis by binding to one or more penicillin-binding proteins, which, in turn, inhibits bacterial growth. Used for septicemia and treatment of gynecologic infections caused by susceptible organisms.
Lower efficacy against gram-positive organisms.
Lower efficacy against gram-positive organisms.
Third-generation cephalosporin with gram-negative spectrum. Lower efficacy against gram-positive organisms.

Adult

Moderate-to-severe infections: 1-2 g IV/IM q6-8h
Life-threatening infections: 1-2 g IV/IM q4h

Pediatric

Infants and children: 50-180 mg/kg/d IV/IM divided q4-6h
>12 years: Administer as in adults

Probenecid may increase levels; coadministration with furosemide and aminoglycosides may increase nephrotoxicity

Pregnancy

B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals

Precautions

Adjust dose in severe renal insufficiency (high doses may cause CNS toxicity); superinfections, and promotion of nonsusceptible organisms may occur with prolonged use or repeated therapy; has been associated with severe colitis


Ceftazidime (Ceptaz, Fortaz, Tazicef, Tazidime)

Third-generation cephalosporin with broad-spectrum, gram-negative activity, including Pseudomonas; lower efficacy against gram-positive organisms; higher efficacy against resistant organisms. Arrests bacterial growth by binding to one or more penicillin-binding proteins, which, in turn, inhibits final transpeptidation step of peptidoglycan synthesis in bacterial cell wall synthesis, thus inhibiting cell wall biosynthesis. Condition of the patient, severity of the infection, and susceptibility of the microorganism should determine proper dose and route of administration.

Adult

250 mg to 2 g IV/IM q8-12h

Pediatric

Neonates: 30 mg/kg IV q12h
Infants and children: 30-50 mg/kg/dose IV q8h; not to exceed 6 g/d
Adolescents: Administer as in adults

Nephrotoxicity may increase with aminoglycosides, furosemide, and ethacrynic acid; probenecid may increase ceftazidime levels

Pregnancy

B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals

Precautions

Adjust dose in severe renal insufficiency (high doses may cause CNS toxicity); superinfections, and promotion of nonsusceptible organisms may occur with prolonged use or repeated therapy


Ceftriaxone (Rocephin)

Third-generation cephalosporin with broad-spectrum, gram-negative activity; lower efficacy against gram-positive organisms; higher efficacy against resistant organisms. Bactericidal activity results from inhibiting cell wall synthesis by binding to one or more penicillin binding proteins. Exerts antimicrobial effect by interfering with synthesis of peptidoglycan, a major structural component of bacterial cell wall. Bacteria eventually lyse due to the ongoing activity of cell wall autolytic enzymes while cell wall assembly is arrested.
Highly stable in presence of beta-lactamases, both penicillinase and cephalosporinase, of gram-negative and gram-positive bacteria. Approximately 33-67% of dose excreted unchanged in urine, and remainder secreted in bile and ultimately in feces as microbiologically inactive compounds. Reversibly binds to human plasma proteins, and binding have been reported to decrease from 95% bound at plasma concentrations <25 mcg/mL to 85% bound at 300 mcg/mL.

Adult

Uncomplicated infections: 250 mg IM once; not to exceed 4 g
Severe infections: 1-2 g IV qd, or divided bid; not to exceed 4 g/d

Pediatric

Neonates >7 d: 25-50 mg/kg/d IV/IM; not to exceed 125 mg/d
Infants and children: 50-75 mg/kg/d IV/IM divided q12h; not to exceed 2 g/d

Probenecid may increase levels; coadministration with ethacrynic acid, furosemide, and aminoglycosides may increase nephrotoxicity; simultaneous administration with IV calcium-containing solutions may cause precipitation, thoroughly flush infusion lines between ceftriaxone and calcium

Documented hypersensitivity; hyperbilirubinemic neonates, particularly those who are premature; neonates ≥ 28 d if they receive calcium-containing IV products

Pregnancy

B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals

Precautions

Adjust dose in severe renal insufficiency (high doses may cause CNS toxicity); superinfections and promotion of nonsusceptible organisms may occur with prolonged use or repeated therapy; caution in breastfeeding women; may displace bilirubin from albumin binding sites, increasing the risk of kernicterus; caution with gallbladder, biliary tract, liver, or pancreatic disease; caution in patients with history of colitis or penicillin hypersensitivity

Antibiotic, Cephalosporin (Second Generation)


Cefuroxime (Ceftin, Kefurox, Zinacef)

Second-generation cephalosporin maintains gram-positive activity of first-generation cephalosporins; adds activity against P mirabilis, H influenzae, E coli, K pneumoniae, and M catarrhalis.
Binds to penicillin-binding proteins and inhibits final transpeptidation step of peptidoglycan synthesis, resulting in cell wall death. Condition of patient, severity of infection, and susceptibility of microorganism determine proper dose and route of administration. Resists degradation by beta-lactamase.

Adult

250-500 mg PO bid for 10 d
Alternatively, 750-1500 mg IV/IM q8h; not to exceed 6 g/24h
Uncomplicated gonorrhea: 1 g PO once as single dose
Note: Administer for 20 d with Lyme disease

Pediatric

Children:
Tab: 125-250 mg PO bid for 10 d
Susp: 20-30 mg/kg/d PO divided bid for 10 d
Adolescents: Administer as in adults
Note: Administer for 20 d with Lyme disease

Disulfiramlike reactions may occur when alcohol is consumed within 72 h after taking cefuroxime; may increase hypoprothrombinemic effects of anticoagulants; may increase nephrotoxicity in patient receiving potent diuretics such as loop diuretics; coadministration with aminoglycosides increase nephrotoxic potential

Pregnancy

B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals

Precautions

Reduce dosage by half if CrCl 10-30 mL/min, and by 3/4 if <10 mL/min (high doses may cause CNS toxicity); bacterial or fungal overgrowth of nonsusceptible organisms may occur with prolonged or repeated therapy

Antibiotic, Quinolone


Ciprofloxacin (Cipro)

Fluoroquinolone that inhibits bacterial DNA synthesis and, consequently, growth, by inhibiting DNA gyrase and topoisomerases, which are required for replication, transcription, and translation of genetic material. Quinolones have broad activity against gram-positive and gram-negative aerobic organisms. Has no activity against anaerobes. Continue treatment for at least 2 d (7-14 d typical) after signs and symptoms have disappeared.

Adult

250-500 mg PO bid for 7-14 d

Pediatric

<18 years: Not recommended
>18 years: Administer as in adults

Antacids, iron salts, and zinc salts may reduce serum levels; administer antacids 2-4 h before or after taking fluoroquinolones; cimetidine may interfere with metabolism of fluoroquinolones; ciprofloxacin reduces therapeutic effects of phenytoin; probenecid may increase ciprofloxacin serum concentrations
May increase toxicity of theophylline, caffeine, cyclosporine, and digoxin (monitor digoxin levels); may increase effects of anticoagulants (monitor PT)

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Dosage adjustments (adult adjustments)
CrCl (mL/min) <10: 50% of PO or IV dose q12h
HD: 0.25-0.5 g PO or 0.2-0.4 g IV q12h
During peritoneal dialysis: 0.25-0.5 g PO or 0.2-0.4 g IV q8h
In prolonged therapy, perform periodic evaluations of organ system functions (eg, renal, hepatic, hematopoietic); adjust dose in renal function impairment; superinfections may occur with prolonged or repeated antibiotic therapy
Not drug of first choice in pediatrics due to increased incidence of adverse events compared with controls, including arthropathy; no data on dose for pediatric patients with renal impairment (ie, CrCl <50 mL/min)
Fluoroquinolones associated with increased risk of tendinitis and tendon rupture in all ages; risk is further increased in older patients usually >60 y, in patients taking corticosteroids, and in patients with kidney, heart, or lung transplants


Levofloxacin (Levaquin)

Used to treat community-acquired pneumonia caused by S aureus, S pneumoniae (including penicillin-resistant strains), H influenzae, H parainfluenzae, Klebsiella pneumoniae, M catarrhalis, C pneumoniae, Legionella pneumophila, or Mycoplasma pneumoniae. Fluoroquinolones should be used empirically in patients likely to develop exacerbation due to resistant organisms to other antibiotics. Rapidly becoming a popular choice in pneumonia. This is the L stereoisomer of the D/L parent compound ofloxacin, the D form being inactive. Good monotherapy with extended coverage against Pseudomonas species and excellent activity against pneumococcus. Agent acts by inhibition of DNA gyrase activity. PO form has bioavailability that reportedly is 99%.

Adult

500 mg PO/IV qd for 7-14 d

Pediatric

<18 years: Not recommended
>18 years: Administer as in adults

Antacids, iron salts, and zinc salts may reduce serum levels; administer antacids 2-4 h before or after taking fluoroquinolones; cimetidine may interfere with metabolism of fluoroquinolones; levofloxacin reduces therapeutic effects of phenytoin; probenecid may increase levofloxacin serum concentrations

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

In prolonged therapy, perform periodic evaluations of organ system functions (eg, renal, hepatic, hematopoietic); adjust dose in renal function impairment; superinfections may occur with prolonged or repeated antibiotic therapy


Moxifloxacin (Avelox)

Inhibits the A subunits of DNA gyrase, resulting in inhibition of bacterial DNA replication and transcription.

Adult

400 mg PO/IV qd

Pediatric

<18 years: Not recommended
>18 years: Administer as in adults

Antacids and electrolyte supplements reduce absorption; loop diuretics, probenecid, and cimetidine increase serum levels; NSAIDs enhance CNS stimulating effect
May increase toxicity of theophylline, caffeine, cyclosporine, and digoxin (monitor digoxin levels); may increase effects of anticoagulants (monitor PT); ferrous sulfate decreases bioavailability (administer moxifloxacin 4 h prior or 8 h following ferrous sulfate); coadministration with drugs that prolong QTc interval (eg, quinidine, procainamide, amiodarone, sotalol, erythromycin, TCAs) increases risk of life-threatening arrhythmia

Documented hypersensitivity; known Q-T prolongation, concurrent administration of drugs that cause Q-T prolongation

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

In prolonged therapy, perform periodic evaluations of organ system functions (eg, renal, hepatic, hematopoietic); superinfections may occur with prolonged or repeated antibiotic therapy; fluoroquinolones have induced seizures in CNS disorders and caused tendinitis or tendon rupture

Antibiotic, Tetracycline Derivative


Doxycycline (Bio-Tab, Doryx, Doxy, Periostat, Vibramycin, Vibra-Tabs)

Broad-spectrum, synthetically derived bacteriostatic antibiotic in the tetracycline class. Almost completely absorbed, concentrates in bile, and is excreted in urine and feces as a biologically active metabolite in high concentrations.
Inhibits protein synthesis and, thus, bacterial growth by binding to 30S and possibly 50S ribosomal subunits of susceptible bacteria. May block dissociation of peptidyl t-RNA from ribosomes, causing RNA-dependent protein synthesis to arrest.
Alternative agent for patients who cannot be given macrolides or penicillins.

Adult

100 mg PO bid for 10 d or until afebrile for 3-5 d

Pediatric

<8 years: Not recommended
>8 years: 2-5 mg/kg/d PO qd or divided bid; not to exceed 200 mg/d

Bioavailability decreases with antacids containing aluminum, calcium, magnesium, iron, or bismuth subsalicylate; tetracyclines can increase hypoprothrombinemic effects of anticoagulants; tetracyclines can decrease effects of oral contraceptives, causing breakthrough bleeding and increased risk of pregnancy

Documented hypersensitivity; severe hepatic dysfunction

Pregnancy

D - Fetal risk shown in humans; use only if benefits outweigh risk to fetus

Precautions

Photosensitivity may occur with prolonged exposure to sunlight or tanning equipment; reduce dose in renal impairment; consider drug serum level determinations in prolonged therapy; tetracycline use during tooth development (last half of pregnancy through age 8 y) can cause permanent discoloration of teeth; Fanconilike syndrome may occur with outdated tetracyclines

Antibiotic, Carbapenem


Ertapenem (Invanz)

Bactericidal activity results from inhibition of cell wall synthesis and is mediated through ertapenem binding to penicillin binding proteins. Stable against hydrolysis by a variety of beta-lactamases, including penicillinases, cephalosporinases, and extended-spectrum beta-lactamases. Hydrolyzed by metallo-beta-lactamases.

Adult

1 g qd for 14 d if IV and 7 d if IM; infuse over 30 min if IV
CrCl <30 mL/min/1.73 m2: 500 mg IV qd

Pediatric

<3 months: Not established
3 months to 12 years: 15 mg/kg IV q12h; not to exceed 1 g/d
>12 years: Administer as in adults

Probenecid may reduce renal clearance of ertapenem and increase half-life but benefit is minimum and does not justify coadministration

Documented hypersensitivity to drug or amide type anesthetics

Pregnancy

B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals

Precautions

Pseudomembranous colitis may occur; seizures and CNS adverse reactions may occur; when using with lidocaine to administer intramuscularly, avoid inadvertent injection into blood vessel; decrease dose in renal failure; serious and occasionally fatal hypersensitivity reactions may occur with beta-lactams, caution with previous hypersensitivity reactions to penicillin, cephalosporins, other beta-lactams, or other allergens; do not mix or co-infuse in same IV line as other medications; do not mix with dextrose containing diluents


Imipenem and cilastatin (Primaxin)

For treatment of multiple organism infections in which other agents do not have wide spectrum coverage or are contraindicated due to potential for toxicity.

Adult

Base initial dose on severity of infection, and administer in equally divided doses; dose may range from 250-500 mg q6h IV for a maximum of 3-4 g/d
Alternatively, 500-750 mg q12h IM or intra-abdominally

Pediatric

Infants >3 months and children <12 years: 15-25 mg/kg/dose IV q6h
Fully susceptible organisms: Not to exceed 2 g/d
Infections with moderately susceptible organisms: Not to exceed 4 g/d
>12 years: Administer as in adults

Coadministration with cyclosporine may increase adverse CNS effects of both agents; coadministration with ganciclovir may result in generalized seizures

Documented hypersensitivity; known hypersensitivity to amide local anesthetics; children with CNS infections (increased seizure risk); children <30 kg with renal impairment (lack of data)

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Adjust dose in renal insufficiency (adult adjustments)
CrCl (mL/min) 80-50: 0.5 g q6-8h
CrCl 50-10: 0.5 g q8-12h
HD: 0.25-0.5 g after HD, then q12h
Adjust dose in renal insufficiency; avoid use in children <12 y with CNS infections
Caution with history of seizures, hypersensitivity to penicillins, cephalosporins, or other beta-lactam antibiotics


Meropenem (Merrem IV)

Bactericidal broad-spectrum carbapenem antibiotic that inhibits cell wall synthesis. Effective against most gram-positive and gram-negative bacteria.
Has slightly increased activity against gram-negatives and slightly decreased activity against staphylococci and streptococci compared with imipenem.

Adult

1 g IV q8h

Pediatric

40 mg/kg IV q8h

Probenecid may inhibit renal excretion, increasing meropenem levels

Pregnancy

B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals

Precautions

Dosage adjustments (adult adjustments)
CrCl (mL/min) 10-50: 0.5-1 g q12h
CrCl <10: 0.5 g/d
HD: As for CrCl <10, with an extra 0.5 g after HD
Pseudomembranous colitis and thrombocytopenia may occur, requiring immediate discontinuation of medication

Antibiotic, Aminoglycoside


Gentamicin (Gentacidin)

Aminoglycoside antibiotic for gram-negative coverage. Used in combination with both an agent against gram-positive organisms and one that covers anaerobes.
Not the DOC. Consider if penicillins or other less toxic drugs are contraindicated, when clinically indicated, and in mixed infections caused by susceptible staphylococci and gram-negative organisms.
Dosing regimens are numerous. Adjust dose based on CrCl and changes in volume of distribution. May be administered IV/IM.

Adult

Serious infections and normal renal function: 3 mg/kg/d IV q8h
Loading dose: 1-2.5 mg/kg IV q8h
Maintenance dose: 1-1.5 mg/kg IV q8h
Extended-dosing regimen for life-threatening infections: 5 mg/kg/d IV/IM q6-8h
Follow each regimen by at least a trough level drawn on the third or fourth dose (0.5 h before dosing); may draw a peak level 0.5 h after 30-min infusion

Pediatric

<5 years: 2.5 mg/kg/dose IV/IM q8h
>5 years: 1.5-2.5 mg/kg/dose IV/IM q8h or 6-7.5 mg/kg/d divided q8h; not to exceed 300 mg/d; monitor as in adults

Coadministration with other aminoglycosides, cephalosporins, penicillins, and amphotericin B may increase nephrotoxicity; because aminoglycosides enhance effects of neuromuscular blocking agents prolonged respiratory depression may occur; coadministration with loop diuretics may increase auditory toxicity of aminoglycosides; possible irreversible hearing loss of varying degrees may occur (monitor regularly)

Documented hypersensitivity; non–dialysis-dependent renal insufficiency

Pregnancy

D - Fetal risk shown in humans; use only if benefits outweigh risk to fetus

Precautions

Narrow therapeutic index (not intended for long-term therapy); caution in renal failure (not on dialysis), myasthenia gravis, hypocalcemia, and conditions that depress neuromuscular transmission; adjust dose in renal impairment

Antibiotic, Oxazolidinone


Linezolid (Zyvox)

Prevents formation of functional 70S initiation complex, which is essential for bacterial translation process. Bacteriostatic against enterococci and staphylococci and bactericidal against most strains of streptococci. Used as alternative in patients allergic to vancomycin and for treatment of vancomycin-resistant enterococci.

Adult

400-600 mg PO/IV q12h for 10-28 d

Pediatric

Preterm neonate <7 days: 10 mg/kg PO/IV q12h
Term neonates-12 years: 10 mg/kg PO/IV q8h
>12 years: Administer as in adults

May cause hypertension when used concomitantly with adrenergic agents, including pseudoephedrine, sympathomimetic agents, vasopressor, or dopaminergic agents (reduce dose of dopamine or epinephrine if concurrent use required); serotonin syndrome may occur if used concomitantly with serotonergic agents, including TCAs, meperidine, dextromethorphan, trazodone, venlafaxine, and selective serotonin reuptake; may cause myelosuppression or pseudomembranous colitis inhibitors

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Has mild MAOI properties and has potential to have same interactions as other MAOIs; caution in uncontrolled hypertension, pheochromocytoma, carcinoid syndrome, or untreated hyperthyroidism, and patients who are at increased risk for bleeding, have preexisting thrombocytopenia, receive concomitant medications that may decrease platelet count or function, or who may require >2 wk of therapy (monitor platelet counts); unnecessary use may lead to development of resistance to drug; may cause peripheral or optic neuropathy

Antibiotic, Sulfonamide Derivative


Sulfamethoxazole and trimethoprim (Bactrim, Bactrim DS, Cotrim, Cotrim DS, Septra, Septra DS)

Inhibits bacterial synthesis of dihydrofolic acid by competing with paraaminobenzoic acid, inhibiting folic acid synthesis. Results in inhibition of bacterial growth. Antibacterial activity of TMP-SMZ includes common urinary tract pathogens, except P aeruginosa.

Adult

160 mg TMP/800 mg SMZ PO bid for 10 d

Pediatric

<2 months: Not recommended
>2 months: 8 mg TMP/kg/d divided bid

May increase PT when used with warfarin (perform coagulation tests and adjust dose accordingly); coadministration with dapsone may increase blood levels of both drugs; coadministration of diuretics increases incidence of thrombocytopenia purpura in elderly persons; phenytoin levels may increase with coadministration; may potentiate effects of methotrexate in bone marrow depression; hypoglycemic response to sulfonylureas may increase with coadministration; may increase levels of zidovudine

Documented hypersensitivity; megaloblastic anemia due to folate deficiency; age <2 mo

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Do not use during last trimester of pregnancy owing to potential toxicity to newborn (eg, jaundice, hemolytic anemia, kernicterus)
Dosage adjustments (adult adjustments)
CrCl (mL/min) 80-50: Recommended IV dose q18h
CrCl 50-10: Recommended IV dose q24h
CrCl <10: Not recommended
HD: 4-5 mg/kg after HD
During peritoneal dialysis: 0.16-0.8 g q48h
Discontinue at first appearance of rash or sign of adverse reaction; obtain CBC counts frequently; discontinue therapy if significant hematologic changes occur; goiter, diuresis, and hypoglycemia may occur with sulfonamides; prolonged IV infusions or high doses may cause bone marrow depression (if signs occur, give 5-15 mg/d leucovorin); caution in folate deficiency (eg, chronic alcoholism, elderly persons, those receiving anticonvulsant therapy, or those with malabsorption syndrome); hemolysis may occur in G-6-PD deficiency; AIDS patients may not tolerate or respond to TMP-SMZ; caution in renal or hepatic impairment (perform urinalyses and renal function tests during therapy); give fluids to prevent crystalluria and stone formation

Human Activated Protein C, Recombinant


Drotrecogin alfa (Xigris)

Indicated for reduction of mortality in patients with severe sepsis associated with acute organ dysfunction and at high risk of death. Recombinant form of human Activated Protein C that exerts antithrombotic effect by inhibiting Factors Va and VIIIa. Has indirect profibrinolytic activity by inhibiting plasminogen activator inhibitor-1 (PAI-1) and limiting formation of activated thrombin-activatable-fibrinolysis-inhibitor. May exert anti-inflammatory effect by inhibiting human TNF production by monocytes, blocking leukocyte adhesion to selectins, and limiting thrombin-induced inflammatory responses within microvascular endothelium.

Adult

24 mcg/kg/h IV continuous infusion for 96 h; ideally, initiate within 48 h of sepsis onset

Pediatric

Not established

None reported; coadministration with drugs that affect hemostasis may increase risk of bleeding (eg, warfarin, heparin, thrombolytics, glycoprotein IIb/IIIa inhibitors)

Documented hypersensitivity; increased risk of bleeding (eg, active internal bleeding, recent hemorrhagic stroke, recent intraspinal or intracranial surgery, recent or current trauma, presence of epidural catheter, intracranial neoplasm, cerebral herniation, severe head trauma)

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Bleeding is most common serious adverse effect; caution with conditions that increase risk of bleeding, including INR >3, concurrent therapeutic heparin (>15 U/kg/h), within 6 wk of GI bleeding episode, within 3 d of thrombolytic therapy, within 7 d of platelet inhibitors administration, within 3 mo of ischemic stroke, intracranial arteriovenous malformation, or aneurysm, known bleeding diathesis, and/or chronic severe hepatic disease; stop infusion if clinically significant bleeding occurs

Glucocorticoid


Hydrocortisone (Cortef, Hydrocort, Hydrocortone)

DOC because of mineralocorticoid activity and glucocorticoid effects.

Adult

100 mg IV bolus, followed by continuous infusion of 100 mg q8h for 24-48 h; once patient is stable, initiate PO hydrocortisone (50 mg q8h for another 48 h; may taper dose to 30-50 mg/d in divided doses)

Pediatric

<12 years: 1-2 mg/kg IV bolus, followed by 25-150 mg/d divided q6-8h
>12 years: 1-2 mg/kg IV bolus, followed by 150-250 mg/d divided q6-8h

CYP450 2D6 and 3A3/4 substrate; corticosteroid clearance may increase with phenytoin, barbiturates, or rifampin treatment or decrease with estrogens; cholestyramine may decrease AUC; corticosteroids may increase digitalis toxicity secondary to hypokalemia; coadministration with potassium-depleting agents (eg, diuretics) may increase risk of hypokalemia; corticosteroids may decrease growth-promoting effect of GH; decreases effects of salicylates and vaccines used for immunization; monitor for hypokalemia with coadministration of diuretics or amphotericin B; antagonizes effects of anticholinergics; may increase anticoagulant effects of warfarin; decreases hypoglycemic effects of sulfonylureas and insulin; increases toxicity of cyclosporine

Documented hypersensitivity; viral, fungal, or tubercular skin infections

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Caution in hyperthyroidism, osteoporosis, peptic ulcer, cirrhosis, nonspecific ulcerative colitis, diabetes, and myasthenia gravis

More on Pneumonia, Bacterial

Overview: Pneumonia, Bacterial
Differential Diagnoses & Workup: Pneumonia, Bacterial
Treatment & Medication: Pneumonia, Bacterial
Follow-up: Pneumonia, Bacterial
References

References

  1. Stedman's Medical Dictionary. 27th. Lippincott, Williams and Wilkins; 2009:[Full Text].

  2. Gharib AM, Stern EJ. Radiology of pneumonia. Med Clin North Am. Nov 2001;85(6):1461-91, x. [Medline].

  3. Tarver RD, Teague SD, Heitkamp DE, Conces DJ Jr. Radiology of community-acquired pneumonia. Radiol Clin North Am. May 2005;43(3):497-512, viii. [Medline].

  4. Anand N, Kollef MH. The alphabet soup of pneumonia: CAP, HAP, HCAP, NHAP, and VAP. Semin Respir Crit Care Med. Feb 2009;30(1):3-9. [Medline].

  5. El Solh AA. Nursing home-acquired pneumonia. Semin Respir Crit Care Med. Feb 2009;30(1):16-25. [Medline].

  6. Kuti JL, Shore E, Palter M, Nicolau DP. Tackling empirical antibiotic therapy for ventilator-associated pneumonia in your ICU: guidance for implementing the guidelines. Semin Respir Crit Care Med. Feb 2009;30(1):102-15. [Medline].

  7. Eggimann P, Pittet D. Infection control in the ICU. Chest. Dec 2001;120(6):2059-93. [Medline].

  8. Marik PE. Aspiration pneumonitis and aspiration pneumonia. N Engl J Med. Mar 1 2001;344(9):665-71. [Medline].

  9. Forgie S, Marrie TJ. Healthcare-associated atypical pneumonia. Semin Respir Crit Care Med. Feb 2009;30(1):67-85. [Medline].

  10. [Guideline] Mandell LA, Wunderink RG, Anzueto A, et al. Infectious Diseases Society of America/American Thoracic Society consensus guidelines on the management of community-acquired pneumonia in adults. Clin Infect Dis. Mar 1 2007;44 Suppl 2:S27-72. [Medline].

  11. Centers for Disease Control. Health Topics A-Z. Available at http://www.cdc.gov/az. Accessed 20 June 2009.

  12. Restrepo MI, Anzueto A. The role of gram-negative bacteria in healthcare-associated pneumonia. Semin Respir Crit Care Med. Feb 2009;30(1):61-6. [Medline].

  13. Dennis DT, Inglesby TV, Henderson DA, et al. Tularemia as a biological weapon: medical and public health management. JAMA. Jun 6 2001;285(21):2763-73. [Medline].

  14. Mizgerd JP. Acute lower respiratory tract infection. N Engl J Med. Feb 14 2008;358(7):716-27. [Medline].

  15. Hussain AN and Kumar V. The Lung. In: Robbins and Cotran Pathologic Basis of Disease. 7th. Elsevier Saunders; 2005:Chap 15.

  16. Rubins JB, Janoff EN. Pneumolysin: a multifunctional pneumococcal virulence factor. J Lab Clin Med. Jan 1998;131(1):21-7. [Medline].

  17. Sadikot RT, Blackwell TS, Christman JW, Prince AS. Pathogen-host interactions in Pseudomonas aeruginosa pneumonia. Am J Respir Crit Care Med. Jun 1 2005;171(11):1209-23. [Medline].

  18. Rello J, Ollendorf DA, Oster G, et al. Epidemiology and outcomes of ventilator-associated pneumonia in a large US database. Chest. Dec 2002;122(6):2115-21. [Medline].

  19. National Center for Health Statistics. 2006 National Hospital Discharge Survey. Centers for Disease Control and Prevention. July 2008.

  20. American Lung Association. Trends in pneumonia and influenza morbidity and mortality. September 2008..

  21. National Center for Health Statistics. Deaths: Final data for 2005. Centers for Disease Control and Prevention. April 2008.

  22. Slovis BS and Brigham KL. Approach to the patient with respiratory disease. In: Cecil Essentials of Medicine. 6th. WB Saunders Co; 2004:Chap 14.

  23. Skerrett SJ. Diagnostic testing for community-acquired pneumonia. Clin Chest Med. Sep 1999;20(3):531-48. [Medline].

  24. Smith PR. What diagnostic tests are needed for community-acquired pneumonia?. Med Clin North Am. Nov 2001;85(6):1381-96. [Medline].

  25. Lim WS, van der Eerden MM, Laing R, et al. Defining community acquired pneumonia severity on presentation to hospital: an international derivation and validation study. Thorax. May 2003;58(5):377-82. [Medline].

  26. Knaus WA, Draper EA, Wagner DP, Zimmerman JE. APACHE II: a severity of disease classification system. Crit Care Med. Oct 1985;13(10):818-29. [Medline].

  27. Cooper MS, Stewart PM. Corticosteroid insufficiency in acutely ill patients. N Engl J Med. Feb 20 2003;348(8):727-34. [Medline].

  28. Rivers E, Nguyen B, Havstad S, et al. Early goal-directed therapy in the treatment of severe sepsis and septic shock. N Engl J Med. Nov 8 2001;345(19):1368-77. [Medline].

  29. Ketai L, Jordan K, Marom EM. Imaging infection. Clin Chest Med. Mar 2008;29(1):77-105, vi. [Medline].

  30. Gotway MB, Reddy GP, Webb WR, Elicker BM, Leung JW. High-resolution CT of the lung: patterns of disease and differential diagnoses. Radiol Clin North Am. May 2005;43(3):513-42, viii. [Medline].

  31. Fine MJ, Auble TE, Yealy DM, et al. A prediction rule to identify low-risk patients with community-acquired pneumonia. N Engl J Med. Jan 23 1997;336(4):243-50. [Medline].

  32. [Guideline] The Joint Commission and the Centers for Medicare and Medicaid Services. Specifications Manual for National Hospital Quality Measures. Version 2.6b. April 2009.

  33. Lam AP, Wunderink RG. The role of MRSA in healthcare-associated pneumonia. Semin Respir Crit Care Med. Feb 2009;30(1):52-60. [Medline].

Further Reading

Keywords

bacterial pneumonia, pneumonia, pneumococcus, Streptococcus pneumoniae, S pneumoniae, Haemophilus influenzae, H influenzae, Staphylococcus aureus, S aureus, Legionella, Legionella pneumophila, Mycoplasma, Mycoplasma pneumoniae,  Chlamydophila psittaci, Coxiella burnetii, C burnetii, Pseudomonas, Klebsiella, Klebsiella pneumoniae, K pneumoniae, Moraxella catarrhalis, M catarrhalis, Nocardia, Escherichia coli, Enterobacter, Serratia species, Bacteroides, Peptostreptococcus, Fusobacterium species, hospital-acquired pneumonia, community-acquired pneumonia, CAP, nosocomial pneumonia, viral pneumonia, typical pneumonia, atypical pneumonia, lobular pneumonia, lobar pneumonia, bronchial pneumonia

Contributor Information and Disclosures

Author

Nader Kamangar, MD, FACP, FCCP, FAASM, Associate Professor of Clinical Medicine, Division of Pulmonary, Critical Care and Sleep Medicine, Multi-campus Pulmonary and Critical Care Fellowship Program, University of California, Los Angeles, David Geffen School of Medicine; Medical Director, Hospitalist/Intensivist Program, Olive View-UCLA Medical Center; Associate Program Director, Combined Pulmonary and Critical Care Fellowship Program, Cedars-Sinai/Olive View-UCLA Medical Center/West Los Angeles Veterans Affairs Medical Center
Nader Kamangar, MD, FACP, FCCP, FAASM is a member of the following medical societies: American Academy of Sleep Medicine, American Association of Bronchology, American College of Chest Physicians, American College of Physicians, American Lung Association, American Medical Association, American Thoracic Society, California Thoracic Society, and Society of Critical Care Medicine
Disclosure: Nothing to disclose.

Coauthor(s)

Christina Rager, MD, Resident Physician, Internal and Emergency Medicine, Olive View-University of California at Los Angeles Medical Center
Christina Rager, MD is a member of the following medical societies: American College of Physicians, American Medical Student Association/Foundation, and Phi Beta Kappa
Disclosure: Nothing to disclose.

Sat Sharma, MD, FRCPC, Professor and Head, Division of Pulmonary Medicine, Department of Internal Medicine, University of Manitoba; Site Director, Respiratory Medicine, St Boniface General Hospital
Sat Sharma, MD, FRCPC is a member of the following medical societies: American Academy of Sleep Medicine, American College of Chest Physicians, American College of Physicians-American Society of Internal Medicine, American Thoracic Society, Canadian Medical Association, Royal College of Physicians and Surgeons of Canada, Royal Society of Medicine, Society of Critical Care Medicine, and World Medical Association
Disclosure: Nothing to disclose.

Medical Editor

Ryland P Byrd Jr, MD, Professor, Department of Internal Medicine, Division of Pulmonary Medicine and Critical Care Medicine, Program Director of Pulmonary Diseases and Critical Care Medicine Fellowship, James H Quillen College of Medicine, East Tennessee State University; Medical Director of Respiratory Therapy, James H Quillen Veterans Affairs Medical Center
Ryland P Byrd Jr, MD is a member of the following medical societies: American College of Chest Physicians and American Thoracic Society
Disclosure: Nothing to disclose.

Pharmacy Editor

Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: eMedicine Salary Employment

CME Editor

Timothy D Rice, MD, Associate Professor, Departments of Internal Medicine and Pediatrics and Adolescent Medicine, Saint Louis University School of Medicine
Timothy D Rice, MD is a member of the following medical societies: American Academy of Pediatrics and American College of Physicians
Disclosure: Nothing to disclose.

Chief Editor

Zab Mosenifar, MD, Director, Division of Pulmonary and Critical Care Medicine, Director, Women's Guild Pulmonary Disease Institute, Executive Vice Chair, Department of Medicine, Cedars Sinai Medical Center; Professor of Medicine, David Geffen School of Medicine at UCLA
Zab Mosenifar, MD is a member of the following medical societies: American College of Chest Physicians, American College of Physicians, American Federation for Medical Research, and American Thoracic Society
Disclosure: Nothing to disclose.

 
 
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