Joint chemotherapy trials in lepromatous leprosy conducted in Thailand, the Philippines, and Korea.

Chemotherapy trials in lepromatous leprosy using various combinations of existing antileprosy drugs were conducted jointly by Korea, The Philippines, and Thailand. The general objective of these trials was to determine the most effective and practicable regimen or regimens for field application. Lepromatous patients were divided into two groups: Group I was comprised of new, untreated patients infected with dapsone-sensitive Mycobacterium leprae and Group II consisted of relapsed patients with dapsone-resistant disease. Four different regimens were administered to each group for 5 years. Comparison among the regimens was based on antileprotic efficacy, drug safety, acceptability, field practicability, and economic feasibility. No significant differences were noted among the various regimens as judged by the reduction in the bacterial index (BI), clinical response, and change in biopsy index. Toxicity was seen only in the regimens containing prothionamide and rifampin. The regimens were acceptable to the patients and all were found practical for field use. Clofazimine, even in low doses, was found to suppress the frequency and severity of erythema nodosum leprosum. A multidrug regimen effective against both new and relapsed cases of lepromatous leprosy, whether dapsone sensitive or dapsone resistant, is recommended for field use. Given priority, the cost of the regimens is affordable in the three countries.