Pilot study of twice-weekly therapy for pulmonary tuberculosis in Taiwan

Taiwan has never implemented supervised intermittent chemotherapy for pulmonary tuberculosis, and its application and results are unknown. The purpose of this study was to evaluate the efficacy and feasibility of a 62-dose, four-drug, 6-month, twice-weekly regimen administered by directly observed therapy for the treatment of pulmonary tuberculosis.

From January 2004 through December 2006, a total of 116 patients with suspected or confirmed pulmonary tuberculosis were enrolled. Thirty-two of these patients were excluded from the analysis because of drug resistance, negative culture, self withdrawal and drug reactions. Isoniazid, rifampin, pyrazinamide, and ethambutol were administered daily for 2 weeks, followed by twice weekly at a higher dose for 6 weeks. Thereafter, isoniazid, ethambutol and rifampin were administered twice weekly for 18 weeks. Treatment was directly observed by nurses or outreach workers.

Of the 84 evaluable patients, 75 [89.3%, 95% confidence interval (CI): 80.6s-95.0%] patients were considered as successfully treated, three (3.6%, 95% CI: 0.7-10.1%) transferred out, five (6.0%, 95% CI: 2.0-13.3%) were unsuccessful and one (1.2%, 95% CI: 0.03-6.5%) died. Five patients were treatment failure (6.0%, 95% CI: 2.0-13.3%). Three patients had recurrences of pulmonary tuberculosis, and the recurrences were 4, 6 and 15 months after the completion of therapy. Sixpatients (5.2%) had severe adverse drug reactions and had their regimen modified.

Prior to this study, intermittent therapy has not been attempted in Taiwan. This four-drug mostly twice-weeldy pulmonary tuberculosis treatment regimen is efficacious and relatively nontoxic, with a higher treatment success rate and a lower death rate. It considerably simplifies treatment and facilitates the execution of directly observed therapy. The reasons for the relatively high failure rate require further studies.