Dr. Almeida replies
To the Editor:
I thank Dr. Levy for his interesting comments on an earlier submission (1). I believe he is wise to choose daily (not monthly) rifampin for himself. He is right in stating that "persister" Mycobacterium leprae occur regardless of the regimen used. However, this will be poor comfort to patients who are on monthly rifampin. It is nonpersisterM leprae, rather than "persisters," that are worrisome (3). Monthly rifampin is far less effective than daily rifampin against nonpersister M. leprae.
In passing, I am sure that Dr. Levy has persuaded himself adequately of the relevance of mouse foot pad findings to human therapy (6). Particular mouse foot pad findings may be inconvenient, but that is surely no reason to selectively discard them.
Dr. Levy seems to draw comfort from the record of WHO-MDT, based largely on self-healing patients and those already smearnegative after previous treatment. Even placebos might have a fair measure of success under those circumstances. It is more meaningful to analyze results among previously untreated, smear-positive lepromatous patients, when a less comforting picture might emerge (7,8).
Let us consider rifampin and cost-effectiveness. Daily rifampin is effective and the single initial dose of rifampin gives a surprisingly high initial kill (2,4,5). However, monthly rifampin appears no more effective than daily dapsone or clofazimine (2,4,5). If rifampin is continued beyond a single initial dose, it should be given daily or not at all. Monthly rifampin appears superfluous.
- Joel G. Almeida, M.B.B.S., Ph.D.
Consultant in Infectious Disease
P.O. Box 25
Koclaikanal 624101, India
REFERENCES
1. ALMEIDA, J. G. How effective is monthly rifampin? Int. J. Lepr. 60(1992)81-82.
2. ALMEIDA, J. G. A quantitative basis for sustainable anti-Mycobacterium leprae chemotherapy in leprosy control programs. Int. J. Lepr. 60(1992)255-258.
3. GROSSET, J. H. Recent developments in the field of multidrug therapy and future research in chemotherapy of leprosy. Lepr. Rev. 57 Suppl. 3(1986)223-234.
4. GROSSET, J. H. and GUELPA-LAURAS. C. C. Activity of rifampin in infections of normal mice with SI. leprae. Int. J. Lepr. 55(1987)847-851.
5. JI, B., CHEN, J., LU, X., WANG, S., NI, G., HOU, Y., ZHOU, D. and TANG, Q. Antimycobacterial activities of two newer ansamycins, R-76-1 and DL473. Int. J. Lepr. 54(1986)563-577.
6. LEVY, L. Application of the mouse foot pad technique in immunologically normal mice in support of clinical drug trials and a review of earlier clinical drug trials in lepromatous leprosy. Int. J. Lepr. 55 Suppl.(1987)823-829.
7. PATTYN, S. R. Search for effective short-course regimens for the treatment of leprosy. Int. J. Lepr. 61(1993)76-81.
8. VAN BRAKEL, W., KIST, P., NOBLE, S. and O'TOOLE, L. Relapses after MD T for leprosy: a preliminary report of 22 cases in western Nepal. Lepr. Rev. 60(1989)45-50.