TREATMENT OF SHIGELLOSIS .5. COMPARISON OF AZITHROMYCIN AND CIPROFLOXACIN - A DOUBLE-BLIND, RANDOMIZED, CONTROLLED TRIAL

Background: Treatment of shigellosis is currently limited by the high prevalence of multidrug-resistant strains of Shigella. Objective: To d etermine the efficacy of azithromycin in the treatment of shigellosis. Design: Randomized, double-blind clinical trial. Setting: Diarrhea tr eatment center in Dhaka, Bangladesh. Patients: 70 men with shigellosis that had lasted 72 hours or less. Interventions: Patients stayed in t he hospital for 6 days. Thirty-four patients were randomly assigned to receive 500 mg of azithromycin on study day 1, followed by 250 mg onc e daily for 4 days; 36 patients were assigned to receive 500 mg of cip rofloxacin every 12 hours for 5 days. Measurements: Clinical treatment failure was considered to have occurred if frank dysentery persisted for 72 hours after therapy began or if on study day 5 a patient had mo re than six stools, had any bloody-mucoid stools, had more than one wa tery stool, or had an oral body temperature exceeding 37.8 degrees C. Bacteriologic treatment failure was considered to have occurred if Shi gella strains could be isolated from a stool sample after study day 2. Therapy was considered either clinically or bacteriologically success ful in patients who completed therapy and did not meet criteria for fa ilure. Results: Therapy was clinically successful in 28 (82%) patients who received azithromycin and 32 (89%) patients who received ciproflo xacin (difference, -7% [95% CI, -23% to 10%]). Therapy was bacteriolog ically successful in 32 (94%) patients receiving azithromycin and 36 ( 100%) patients receiving ciprofloxacin (difference. -6% [CI, -14% to 2 %]). Peak serum concentrations of azithromycin were equal to the minim um inhibitory concentration (MIG) of the infecting Shigella strains, w hereas serum concentrations of ciprofloxacin were 28 times the MIG. St ool concentrations of both drugs were more than 200 times the MIG. Con clusion: Azithromycin is effective in the treatment of moderate to sev ere shigellosis caused by multidrug-resistant Shigella strains.