viral infection
Azithromycin (Zithromax) Contraindications and Precautions
Azithromycin does not treat viral infection (e.g., common cold). Prescribing azithromycin in the absence of a proven or strongly suspected bacterial infection or a prophylactic indication is unlikely to provide benefit to the patient and increases the risk of the development of drug-resistant bacteria. Patients should be told to complete the full course of treatment, even if they feel better earlier.
Azithromycin can cause rare, but serious allergic reactions, including angioedema and anaphylaxis. There is a risk of cross sensitivity with other macrolide antibiotics. Some patients have a recurrence of allergic symptoms once symptomatic treatment is withdrawn, even though azithromycin therapy is not reinstated. Patients with a known azithromycin or macrolide hypersensitivity should not receive azithromycin.
Oral therapy with azithromycin is not recommend in patients with serious infections (e.g., pneumonia) who are considered to be inappropriate candidates for oral therapy. This includes patients with moderate or severe illness or risk factors such as patients with cystic fibrosis, with nosocomially acquired infections, with known or suspected bacteremia, who require hospitalization, who are elderly or debilitated, or who have significant underlying health problems that may compromise their ability to respond to their illness (including immunodeficiency or functional asplenia).
Since it is primarily eliminated via the liver, azithromycin should be used with caution in patients who have hepatic disease. In addition, hepatotoxicity can result, so liver-function tests should be monitored in patients receiving azithromycin.
Safe use of azithromycin in patients with renal disease has not been determined. Azithromycin should be used cautiously in patients with preexisting renal disease.
Azithromycin should be used with caution in patients with a history of GI disease. Interference with the normal flora of the colon may allow an overgrowth of clostridia. It has been established that a toxin produced by Clostridium difficile is a primary cause of antibiotic-associated colitis. Patients who develop diarrhea while taking or soon after taking azithromycin should be considered for differential diagnosis of antibiotic-associated pseudomembranous colitis. Antibiotic therapy can result in superinfection with non-susceptible organisms. Overgrowth of Candida and fungal infection can occur with azithromycin therapy. Patients should be monitored closely during therapy.
Azithromycin should be used cautiously in patients with QT prolongation. The following adverse reactions have been reported with other macrolide-class antibiotics in patients with prolonged QT intervals: ventricular arrhythmias, including ventricular tachycardia and torsade de pointes.
In multiple-dose clinical trials of oral and intravenous azithromycin, no overall difference in safety and effectiveness was observed between elderly subjects (>=65 years) and younger subjects. Other reported clinical experience has not identified differences in responses between the elderly and younger patients, but greater sensitivity of some older individuals cannot be ruled out.
Azithromycin is classified as FDA pregnancy risk category B. Animal data reveal no teratogenic effects. There are, however, no adequate and well-controlled studies in pregnant women. Because animal studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed. Azithromycin has not been studied for use during labor and delivery. Treatment should be given only if clearly needed.
Azithromycin should be used cautiously in women who are breast-feeding. It is not known if azithromycin is distributed into breast milk.
Direct sunlight (UV) exposure should be minimized during therapy with azithromycin. Photosensitivity has been reported as an allergic reaction to azithromycin. Azithromycin should be discontinued at the first sign of erythema.
Zithromax® (azithromycin for injection) contains a total of 4.96 mEq (114 mg) of sodium per vial. At the usual recommended doses, patients would receive 4.96 mEq (114 mg) of sodium. The sodium amounts should be considered in patients with requirements for sodium restriction or blunted natriuresis to salt loading (i.e., cardiac disease, elderly, or hypertension).
[ Last revised: 9/28/2004 5:41:00 PM ]
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