Problems in the design of medium and long term therapeutic trials

Abstract

The killing of Myco. leprae in vivo and its subsequent lysis are separate functions, both of which are governed by immunity. The first is also effectively achieved by chemotherapy, but it has not been shown that any of the known drugs has any effect on lysis. Any such effect is greatly outweighed by that of immunity even in lepromatous patients. Medium and long term drug trials in leprosy should be concerned with the general progress of the patient and the detection of relapse. It is doubtful whether there are any drugs that warrant the type of trial which is based on an assessment of bacterial lysis. Such trials are complex, time consuming and the resources available are limited. If there is any regimen that justified such a trial present opportunities should not be wasted. In such trials the initial MI need not be a limiting factor.