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Legionnaires Disease: Treatment & Medication
Updated: Jun 1, 2009
- Overview
- Differential Diagnoses & Workup
- Treatment & Medication
- Follow-up
- Multimedia
Treatment
Prehospital Care
- Oxygen therapy is the mainstay of prehospital therapy.
- Intravenous (IV) access and fluid therapy may be indicated for dehydration or septic shock.
- Restraints may be required for patients with altered mental status. Seizure precautions may be indicated.
- Differentiating Legionnaires disease with multiple rigors and altered mental status from a seizure disorder may be possible only through a clinical examination.
Emergency Department Care
- Control the airway as indicated clinically. Support ventilation and oxygenation.
- Rehydrate the patient as indicated, especially in shock or diarrheal disease.
- Antipyretics may be used, as indicated.
- Cardiac monitoring may be required if chest pain, hypotension, bradycardia, or other indicators are present.
- Obtain laboratory specimens (respiratory culture and urine antigen testing), CXR, CT scan, and CSF, as indicated.
- Begin empiric antibiotic therapy as noted below. (Also see the CDC's Legionella Resource Center and Infectious Diseases Society of America's clinical guideline.2 )
Consultations
- Because of the protean presentation of this disease, many different consultations may be indicated.
- General internists, pulmonologists, critical care specialists, cardiologists, gastroenterologists, neurologists, infectious disease specialists, nephrologists, oncologists, and general surgeons may be required at one time or another.
Medication
Standard antibiotic susceptibility tests are not reliable in Legionnaires disease. Resistance to commonly prescribed front-line agents has not been problematic. First-line therapy consists of either fluoroquinolones (levofloxacin) or azithromycin. Erythromycin, with or without rifampin, is effective for Legionnaires disease, but the combined GI manifestations of the disease added to the GI effects of erythromycin may be problematic. For this reason, some specialists prefer doxycycline. Other drugs include cotrimoxazole, tetracycline, and ciprofloxacin. When illness is severe or GI complications preclude the use of oral medications, intravenous antibiotics and hospitalization should be utilized. Duration of therapy depends on the agent utilized as well as the severity of infection and the immunological competence of the patient. Pontiac fever is usually self-limited and does not typically require antibiotic therapy.
Antibiotics
Therapy must cover all likely pathogens in the context of the clinical setting.
Levofloxacin (Levaquin)
Primarily excreted in urine (87% unchanged).
Adult
750 mg PO/IV q24h (duration depends on severity of illness and immunocompromise)
Pediatric
Not applicable
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
Documented hypersensitivity; prolonged QT, antiarrhythmic medications, or proarrhythmic condition; caution with renal impairment
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 disease; tendonitis, tendon rupture in all ages
Azithromycin (Zithromax)
Liver metabolism (CYP 45) with bile excretion (>50% unchanged).
Adult
500 mg daily on day 1, followed by 4 d of 250 mg daily
Pediatric
10 mg/kg/d PO day 1, then 5 mg/kg/d for 4 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; caution with liver or renal impairment; QT prolongation
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
Erythromycin (Ery-Tab, Erythrocin, EES)
Metabolized in liver and excreted primarily by bile. Inhibits RNA-dependent protein synthesis, possibly by stimulating dissociation of peptidyl t-RNA from ribosomes. This inhibits bacterial growth.
Adult
0.5-1 g IV/PO qid for 21 d
Pediatric
50-100 mg/kg/d IV/PO divided qid for 21 d
May increase toxicity of theophylline, digoxin, carbamazepine, and cyclosporine; may potentiate anticoagulant effects of warfarin; lovastatin and simvastatin increase risk of rhabdomyolysis
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; GI side effects are common (give doses pc); discontinue use if nausea, vomiting, malaise, abdominal colic, or fever occur
Doxycycline (Doryx, Bio-Tab)
Second DOC; interferes with bacterial cell wall synthesis during active multiplication, causing cell wall death and resultant bactericidal activity against susceptible bacteria.
Adult
200 mg IV/PO loading dose, followed by 100 mg IV/PO bid; do not inject IM/SC
Pediatric
<8 years: Not recommended
<100 lb (45 kg): 2 mg/lb/d (4.4 mg/kg/d) IV/PO divided bid
>100 lb (45 kg): Administer as in adults
Bioavailability decreases with antacids containing aluminum, calcium, magnesium, iron, or bismuth subsalicylate; can increase hypoprothrombinemic effects of anticoagulants; 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; 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
Rifampin (Rifadin, Rimactane)
DOC to use with erythromycin. Inhibits DNA-dependent RNA polymerase activity in susceptible cells. Specifically, interacts with bacterial RNA polymerase, but does not inhibit mammalian enzyme.
Adult
600 mg PO/IV qd
Pediatric
10-20 mg/kg PO/IV; not to exceed 600 mg/d
Induces microsomal enzymes, which may decrease effects of acetaminophen, oral anticoagulants, barbiturates, benzodiazepines, beta-blockers, chloramphenicol, oral contraceptives, corticosteroids, mexiletine, cyclosporine, digitoxin, disopyramide, estrogens, hydantoins, methadone, clofibrate, quinidine, dapsone, tazobactam, sulfonylureas, theophyllines, tocainide, and digoxin; BP may increase with enalapril; coadministration with isoniazid may result in higher rate of hepatotoxicity than with either agent alone (discontinue one or both agents if alterations in LFTs occur)
Documented hypersensitivity
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
Obtain CBCs and baseline clinical chemistries prior to and throughout therapy; in liver disease, weigh benefits against risk of further liver damage; interruption of therapy and high-dose intermittent therapy are associated with thrombocytopenia that is reversible if therapy is discontinued as soon as purpura occurs; if treatment is continued or resumed after appearance of purpura, cerebral hemorrhage or death may occur
More on Legionnaires Disease |
| Overview: Legionnaires Disease |
| Differential Diagnoses & Workup: Legionnaires Disease |
 Treatment & Medication: Legionnaires Disease |
| Follow-up: Legionnaires Disease |
| Multimedia: Legionnaires Disease |
| References |
| Further Reading |
| « Previous Page | Next Page » |
References
CDC. Summary of notifiable diseases, United States 1995. MMWR Morb Mortal Wkly Rep. Oct 25 1996;44(53):1-87. [Medline].
[Guideline] Mandell LA, Wunderink RG, Anzueto A, Bartlett JG, Campbell GD, Dean NC, 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].
Amsden GW. Treatment of Legionnaires' disease. Drugs. 2005;65(5):605-14. [Medline].
Blanquer J, Blanquer R, Borras R, et al. Aetiology of community acquired pneumonia in Valencia, Spain: a multicentre prospective study. Thorax. Jul 1991;46(7):508-11. [Medline].
CDC. Legionnaires disease associated with a whirlpool spa display--Virginia, September-October, 1996. MMWR Morb Mortal Wkly Rep. Jan 31 1997;46(4):83-6. [Medline].
Cunna B. Legionnaire's disease - Case studies in infectious disease. Emerg Med. 1992;24:227-234.
Falco V, Fernandez de Sevilla T, Alegre J, Ferrer A, Martinez Vazquez JM. Legionella pneumophila. A cause of severe community-acquired pneumonia. Chest. Oct 1991;100(4):1007-11. [Medline].
Lane G, Ferrari A, Dreher HM. Legionnaire's disease: a current update. Medsurg Nurs. Dec 2004;13(6):409-14. [Medline].
Marrie TJ, Haldane EV, Noble MA, Faulkner RS, Martin RS, Lee SH. Causes of atypical pneumonia: results of a 1-year prospective study. Can Med Assoc J. Nov 15 1981;125(10):1118-23. [Medline].
Marston BJ, Lipman HB, Breiman RF. Surveillance for Legionnaires' disease. Risk factors for morbidity and mortality. Arch Intern Med. Nov 14 1994;154(21):2417-22. [Medline].
Palmer L. Legionella pneumonia - Cardiopulmonary problems in the office. Emerg Med. 1992;24:84-94.
Reingold AL. Role of legionellae in acute infections of the lower respiratory tract. Rev Infect Dis. Sep-Oct 1988;10(5):1018-28. [Medline].
Shah A, Check F, Baskin S, Reyman T, Menard R. Legionnaires' disease and acute renal failure: case report and review. Clin Infect Dis. Jan 1992;14(1):204-7. [Medline].
Further Reading
Other resources
Legionellosis Resource Center
Clinical guidelines
Infectious Diseases Society of America/American Thoracic Society consensus guidelines on the management of community-acquired pneumonia in adults. Mandell LA, Wunderink RG, Anzueto A, Bartlett JG, Campbell GD, Dean NC, Dowell SF, File TM Jr, Musher DM, Niederman MS, Torres A, Whitney CG. Infectious Diseases Society of America/American Thoracic Society consensus guidelines on the management of community-acquired pneumonia in adults. Clin Infect Dis 2007 Mar 1;44 Suppl 2:S27-72. [335 references] PubMed
Keywords
Legionnaires disease, Legionnaires' disease, Legionella pneumophila, L pneumophila, atypical pneumonia, pulmonary infection, Pontiac fever, community-acquired bacterial pneumonia, CAP
