Ciprofloxacin once daily versus twice daily for the treatment of pulmonary tuberculosis.

Ciprofloxacin was used as an antituberculous drug in adult patients who could not tolerate standard regimens or had to be treated with alternative combinations for resistance problems. During October 1986 to December 1991, 241 patients received ciprofloxacin in two daily 500 mg doses administered under supervision at 8.30 a.m. and 5 p.m., respectively. This group of patients was submitted to retrospective analysis for tolerability and clinical as well as microbiological efficacy. In January 1992, a once daily regimen with 1,000 mg of ciprofloxacin was introduced in order to simplify drug administration together with the other combination partners and to take advantage of higher drug levels at the site of infection. These patients were followed prospectively for safety and efficacy. Until July 1993, 227 patients with smear-positive pulmonary tuberculosis were included in this open study. Comparative analysis was carried out for a selected group of patients who had remained smear and culture positive for more than 27 days after start of treatment. Fifty-four patients who had received ciprofloxacin twice daily and 35 patients on the once daily regimen were evaluable. Both regimens were equally well tolerated. The once daily regimen was associated with a trend towards earlier conversion to smear negativity and a significantly shorter time to culture negativity. Smears became negative on average within 84 days with the once daily and in 94 days with the twice daily schedule (p = 0.19). Culture negativity occurred at 60 and 76 days in the respective groups (p = 0.0013; log Rank test). Of the patients who received ciprofloxacin twice daily, 33% were still smear and culture positive 90 days after start of treatment compared to only 15% of the patients treated with the once daily schedule. We conclude that ciprofloxacin, given as a single daily dose of 1,000 mg is as safe as two 500 mg doses, more convenient to apply and probably more efficacious.