Objective: To determine whether a single dose, or 2 doses, of ciprofloxacin are as effective as 5-day, 10-dose therapy for the treatment of shigellosis in adult men who are moderately to severely ill.
Design: Randomized, double-blind clinical trial.
Setting: A diarrhea treatment center in the capital city of a developing country, Bangladesh.
Patients: A total of 128 adult men with dysentery of less than 96 hours duration. All had Shigella organisms isolated from a culture of stool.
Interventions: Patients were randomly assigned to receive either a single 1-gram dose of ciprofloxacin at admission to the study (single-dose group; n = 40), a 1-gram dose of ciprofloxacin at admission and 24 hours later (2-dose group; n = 43), or 500 mg of ciprofloxacin every 12 hours for 5 days (10 dose group; n = 35). All patients were hospitalized for 6 days.
Measurements: Stools were collected individually; their character and consistency were recorded and cultured daily. A physical examination and recording of symptoms were done daily, and the temperature was measured every 4 hours. Therapy was considered to have failed in patients who did not have improvement in the signs and symptoms of dysentery after 72 hours of therapy or in patients who on study day 5 had more than nine stools, or more than two watery stools, or were febrile.
Results: There were no treatment failures in the 78 patients infected with species of Shigella other than Shigella dysenteriae type 1. Among the 40 patients infected with S. dysenteriae type 1, treatment failed in 4 of the 10 patients who received single-dose therapy, 2 of the 15 patients who received 2-dose therapy, and none of the 15 patients who received 10-dose therapy (P = 0.017, single-dose therapy group compared with 10-dose group; P = 0.15 for the single-dose group compared with the 2-dose group; P > 0.2 for the 2-dose group compared with the 10-dose group).
Conclusions: A single 1-gram dose of ciprofloxacin is effective therapy for patients infected with species of Shigella other than S. dysenteriae type 1. Single-dose therapy is inferior to 10-dose therapy for treating patients infected with S. dysenteriae type 1.