Medication Summary
Antibiotics are used to treat urinary tract infection (UTI) and, in select patients, to prevent recurrence. Avoid nephrotoxic drugs whenever possible. On occasion, analgesic therapy may be used to provide relief because of voiding symptoms.
Start antibiotics after performing urinalysis and obtaining a urine specimen for culture in patients with UTI. A 7- to 10-day course of antibiotics is recommended, even for an uncomplicated infection. Short-course treatments should be reserved for nontoxic-appearing adolescent girls with UTI. Be aware of increasing rates of antibiotic resistance and the need to choose antibiotic therapy accordingly.
Empiric antibiotics should be chosen for coverage of the most common uropathogens, namely Escherichia coli and Enterococcus, Proteus, and Klebsiella species. Oral antibiotics are adequate therapy for febrile UTIs in young infants and children.
The possibility of antibiotic resistance must be considered when choosing empiric therapy, especially with ampicillin. Knowledge of the local antibiotic resistance helps in guiding antibiotic choice.
A study by Bryce et al that reviewed studies investigating the prevalence of antibiotic resistance in UTI caused by E. coli in children found that the prevalence of resistance is high, particularly in countries outside the Organization for Economic Co-operation and Development (OECD). Resistance in countries outside the OECD was: 79.8% for ampicillin, 60.3% for co-amoxiclav, 26.8% for ciprofloxacin, and 17.0% for nitrofurantoin. [63]
In a study of 607 children with reflux diagnosed by VCUG after a first or second UTI, the subjects were randomized to antibiotic prophylaxis with TMP-SMX or placebo. The risk of recurrences was reduced by 50% in the treatment group (hazard ratio, 0.50; 95% CI, 0.34-0.74). The risk of renal scarring overall did not differ significantly between the groups over 2 years. Also, the occurrence of a subsequent UTI with a TMP-SMX — resistant organism was significantly increased in the treatment group. The children enrolled were aged 2-71 months, a wider age range than the AAP guidelines currently encompass. [64]
Antibiotics
Class Summary
Antibiotics are used to treat bacterial infections of the urinary tract. Empiric antimicrobial therapy must be comprehensive and should cover all likely pathogens in the context of the clinical setting.
Amoxicillin/clavulanate (Augmentin, Augmentin ES-600, Augmentin XR)
This is an oral therapy for infection with susceptible organisms. Amoxicillin inhibits bacterial cell-wall synthesis by binding to penicillin-binding proteins. The addition of clavulanate inhibits beta-lactamase ̶ producing bacteria.
This is a good alternative antibiotic for patients who are allergic to or intolerant of the macrolide class. It is usually well tolerated and is effective against most infectious agents, although it is not effective against Mycoplasma and Legionella species. It has good tissue penetration but does not enter the cerebrospinal fluid (CSF).
For patients over age 3 months, base dosing protocol on amoxicillin content. Because of different amoxicillin/clavulanic acid ratios in the 250-mg tablet (250/125) versus the 250-mg chewable tablet (250/62.5), do not use the 250-mg tablet until the child weighs over 40 kg. The amoxicillin-clavulanate combination is also available as an oral suspension for children. The half-life of the oral form is 1-1.3 hours.
Ampicillin
Ampicillin is a parenteral agent used for initial treatment of patients with acute pyelonephritis who have gram-positive cocci in urinary sediment or in whom no organisms are observed in the urine. It is indicated for UTIs caused by E coli and P mirabilis.
Ceftriaxone
This third-generation cephalosporin is used for initial parenteral therapy for complicated pyelonephritis in pediatric patients beyond the neonatal period. It is indicated for urinary tract infections caused by E coli, Proteus mirabilis, Morganella morganii, P vulgaris, or K pneumoniae.
Cefotaxime
Cefotaxime is a third-generation cephalosporin that is used as initial parenteral therapy for pediatric patients with acute complicated pyelonephritis. It may be used in neonates or jaundiced patients. Dosing every 6-8 hours is required. In infants, a 2- to 8-week regimen also includes ampicillin.
Cephalexin
Cephalexin is a first-generation cephalosporin. This is an oral treatment for bacterial UTI and for prevention of infection in infants younger than 6-8 weeks.
Cefixime (Suprax)
Cefixime is a third-generation cephalosporin used for oral treatment of acute bacterial UTI. By binding to 1 or more penicillin-binding proteins, it arrests bacterial cell-wall synthesis and inhibits bacterial growth.
Cefpodoxime
Cefpodoxime is a third-generation cephalosporin used for oral treatment of acute bacterial UTI. It is indicated for the management of infections caused by susceptible mixed aerobic-anaerobic microorganisms.
Ceftazidime/avibactam (Avycaz)
Indicated for complicated urinary tract infections (cUTIs) including pyelonephritis in adult and pediatric patients aged 3 months or older caused by the following susceptible Gram-negative microorganisms: Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Citrobacter freundii complex, Proteus mirabilis, and Pseudomonas aeruginosa.
Ceftolozane/tazobactam (Zerbaxa)
Indicated for children aged birth and older with complicated urinary tract infections (cUTI), including pyelonephritis, caused by Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, and Pseudomonas aeruginosa.
Gentamicin
This aminoglycoside is used for initial parenteral therapy in patients with bacterial pyelonephritis who are allergic to cephalosporins. For complicated UTI, it is sometimes used in combination with a cephalosporin.
Tobramycin
Tobramycin may be an option for the empiric parenteral treatment of UTI. It is used in skin, bone, and skin-structure infections caused by Staphylococcus aureus, Pseudomonas aeruginosa, and E coli, as well as by Klebsiella, Proteus, and Enterobacter species.
This agent is indicated in the treatment of staphylococcal infections when penicillin or potentially less toxic drugs are contraindicated and when bacterial susceptibility and clinical judgment justify its use. Dosing regimens are numerous and are adjusted on the basis of creatinine clearance (CrCl) and changes in the volume of distribution.
Sulfamethoxazole and trimethoprim (Bactrim, Septra)
This is an oral treatment for bacterial UTI and for prevention of reinfection. It is available as an oral tablet or a suspension.
Trimethoprim
Trimethoprim is an oral antibiotic used for the prevention of urinary tract infection. It is a dihydrofolate reductase inhibitor that prevents the production of tetrahydrofolic acid in bacteria. It is active in vitro against a broad range of gram-positive and gram-negative bacteria, including uropathogens (eg, Enterobacteriaceae and Staphylococcus saprophyticus).
Resistance is usually mediated by decreased cell permeability or by alterations in the structure or amount of dihydrofolate reductase. Trimethoprim demonstrates synergy with sulfonamides, potentiating inhibition of bacterial tetrahydrofolate production.
Nitrofurantoin (Furadantin, Macrobid, Macrodantin)
This is an oral treatment for bacterial infections of the lower urinary tract (cystitis) and for the prevention of reinfection. Nitrofurantoin is a synthetic nitrofuran that interferes with bacterial carbohydrate metabolism by inhibiting acetylcoenzyme A. It is bacteriostatic at low concentrations (5-10 mcg/mL) and is bactericidal at higher concentrations.
Ciprofloxacin (Cipro, Cipro XR)
This agent is a fluoroquinolone that inhibits bacterial DNA synthesis and, consequently, growth by inhibiting DNA gyrase and topoisomerases, enzymes that are required for the replication, transcription, and translation of genetic material. Quinolones have broad activity against gram-positive and gram-negative aerobic organisms. Ciprofloxacin has no activity against anaerobes. Continue treatment for at least 2 days (7-14 days typical) after signs and symptoms have disappeared.
This agent is not a drug of first choice in pediatric patients, because of an increased incidence of adverse events, including arthropathy, compared with controls. No data exist for dose adjustments for pediatric patients with renal impairment.
Analgesics, Other
Class Summary
These agents are used to provide relief from voiding symptoms caused by UTIs.
Acetaminophen (Tylenol, Mapap, Cetafen, Acephen)
Acetaminophen is a nonopioid systemic analgesic used for moderate voiding discomfort caused by UTI.
Ibuprofen (Motrin, Advil, Caldolor, Ibu, Addaprin)
Ibuprofen is a nonsteroidal anti-inflammatory agent that is used to provide symptomatic relief of dysuria.
Analgesics, Urinary
Class Summary
These agents are used to relieve burning, spasticity, and pain during voiding caused by UTIs.
Phenazopyridine (Azo-Standard, Pyridium, Baridium)
Phenazopyridine exerts local topical anesthetic or analgesic action on urinary mucosa. It is used for symptomatic relief of pain, burning, urgency, frequency, and other discomforts arising from irritation of the lower urinary tract mucosa caused by infection, trauma, surgery, endoscopic procedures, passage of sounds, or catheters. Its analgesic action may reduce or eliminate the need for systemic analgesics. When used concomitantly with antibiotics for UTI, phenazopyridine should not be used for longer than 2 days.
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Application of low-risk criteria for and approach to the febrile infant: A reasonable approach for treating febrile infants younger than 2 months who have a temperature of greater than 38°C.
Tables
- Table 1. Urinalysis for Presumptive Diagnosis of Urinary Tract Infection*
- Table 2. Quantitative Urine Culture for the Diagnosis of Urinary Tract Infection*
- Table 3. Antibiotic Agents for Parenteral Treatment of a Urinary Tract Infection
- Table 4. Antibiotic Agents for the Oral Treatment of Urinary Tract Infection
- Table 5. Antibiotic Agents to Prevent Reinfection
Method |
Findings |
Bright-field or phase-contrast microscopy of centrifuged urinary sediment |
Bacteria |
Gram stain of uncentrifuged or centrifuged urinary sediment |
Bacteria |
Nitrite and leukocyte esterase test |
Positive = UTI likely |
Nitrite test |
Positive = UTI probable |
Leukocyte esterase test |
Positive = UTI probable |
*Negative microscopic findings for bacteria do not rule out a UTI, nor do negative results of dipstick testing for nitrite and leukocyte esterase. False-negative nitrite readings are especially common in children. |
|
Method |
Finding |
Suprapubic aspiration |
If a UTI is present, bacteria are likely to be proliferating in bladder urine with growth of any organism except 2000-3000 CFU/mL coagulase-negative staphylococci. |
Catheterization in a girl or midstream, clean-void collection in a circumcised boy |
Febrile infants and children with UTI usually have >50,000 CFU/mL of a single urinary pathogen; however, UTI may be present with 10,000-50,000 CFU/mL of a single organism.* |
Midstream, clean-void collection in a girl or uncircumcised boy |
UTI is indicated when >100,000 CFU/mL of a single urinary pathogen is present in a symptomatic patient. Pyuria usually present. A UTI may be present with 10,000-50,000 CFU/mL of a single bacterium.* |
Any method in a girl or boy |
If the patient is asymptomatic, bacterial growth is usually >100,000 CFU/mL of the same organism on different days. If pyuria is absent, this result probably indicates colonization rather than infection. |
*Patients with urinary frequency (ie, decreased bladder incubation time) are those most likely to have bacteria proliferating in the urinary bladder in the presence of low colony counts. |
|
Drug |
Dosage and Route |
Comment |
Ceftriaxone |
50-75 mg/kg/day IV/IM as a single dose or divided q12h |
Do not use in infants < 6 wk of age; parenteral antibiotic with long half-life; may displace bilirubin from albumin |
Cefotaxime |
150 mg/kg/day IV/IM divided q6-8h |
Safe to use in infants < 6 wk of age; used with ampicillin in infants aged 2-8 wk |
| Ceftolozane/tazobactam | 30 mg/kg IV q8h x7-14 days | Indicated for complicated UTIs approved in children from birth and older; CrCl must be above 50 mL/min/1.73 m2 |
Ampicillin |
100 mg/kg/day IV/IM divided q8h |
Used with gentamicin in neonates < 2 wk of age; for enterococci and patients allergic to cephalosporins |
Gentamicin |
Term neonates < 7 days: 3.5-5 mg/kg/dose IV q24h Infants and children < 5 years: 2.5 mg/kg/dose IV q8h or single daily dosing with normal renal function of 5-7.5 mg/kg/dose IV q24h Children ≥5 y: 2-2.5 mg/kg/dose IV q8h or single daily dosing with normal renal function of 5-7.5 mg/kg/dose IV q24h |
Monitor blood levels and kidney function if therapy extends >48 h |
Note: CrCl = creatinine clearance; IM = intramuscular; IV = intravenous; q = every; UTI = urinary tract infection. |
||
Protocol |
Daily Dosage |
Sulfamethoxazole and trimethoprim (SMZ-TMP) |
30-60 mg/kg SMZ, 6-12 mg/kg TMP divided q12h |
Amoxicillin and clavulanic acid |
20-40 mg/kg divided q8h |
Cephalexin |
50-100 mg/kg divided q6h |
Cefixime |
8 mg/kg q24h |
Cefpodoxime |
10 mg/kg divided q12h |
Nitrofurantoin* |
5-7 mg/kg divided q6h |
*Nitrofurantoin may be used to treat cystitis. It is not suitable for the treatment of pyelonephritis, because of its limited tissue penetration. |
|
Agent |
Single Daily Dose |
Nitrofurantoin * |
1-2 mg/kg PO |
Sulfamethoxazole and trimethoprim (SMZ-TMP) * |
5-10 mg/kg SMZ, 1-2 mg/kg TMP PO |
Trimethoprim |
1-2 mg/kg PO |
*Do not use nitrofurantoin or sulfa drugs in infants younger than 6 weeks. Reduced doses of an oral first-generation cephalosporin, such as cephalexin at 10 mg/kg, may be used until the child reaches age 6 weeks. Ampicillin or amoxicillin are not recommended because of the high incidence of resistant E coli. |
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