| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
LETTER |
Richard Long is with the University of Alberta, Edmonton. Marcella Scalcini is with the Mayo Clinic, Rochester, Minn. Jaime Ollé-Goig is with the Catalan Association for the Prevention and Treatment of Tuberculosis in the Third World (ACTMON), Barcelona, Spain.
Correspondence: Requests for reprints should be sent to Richard Long, MD, Department of Medicine, University of Alberta Hospitals, Room 2E4.21, Walter Mackenzie Centre, 8440 112 St, Edmonton, Alberta, Canada T6G 2B7 (e-mail: richard.long{at}ualberta.ca).
We read with interest the study by Desvarieux et al. reported in the January 2001 issue of the Journal1 and commend them on their efforts to develop flexible approaches to directly observed therapy (DOT), integrating behavioral knowledge, cost considerations, and practicality to improve tuberculosis treatment completion rates and program effectiveness. However, we would urge caution in the wider application of deferred DOT (D-DOT) until more data on outcome and drug resistance can be brought to bear on the approach.
The treatment of tuberculosis aims to achieve 4 major objectives: (1) to provide a lasting cure with few treatment failures and relapses, (2) to rapidly render patients asymptomatic, (3) to rapidly render highly infectious patients noninfectious, and (4) to prevent drug resistance. Regarding objective 1, the authors' treatment outcome analysis is very difficult to interpret, because such a large proportion of the cases were bacillary negative at the outset and because relapse data are not provided. Regarding objectives 2, 3, and 4, the D-DOT regimen is relatively weak, because only the treatment provided in the continuation phase, not in the initial phase, is fully supervised. Interruption of treatment, with discontinuance of 1 or more drugs, either temporarily or permanently, is likely to have a more dire effect on the outcome if it occurs early in the course of treatment when the bacterial count is high. The International Union Against Tuberculosis and Lung Disease goes so far as to recommend that all treatment containing rifampin and pyrazinamide be administered under the direct observation of health care workers, in most cases on an ambulatory basis.2
The authors must also appreciate that patients who responded to 4 weeks of 3 drugs in the intensive phase (the majority) did not receive pyrazinamide in the second 4 weeks of the intensive phase. Moreover, the dose of isoniazid in the twice-weekly protocol was only 600 mg (10 mg/kg). The American Thoracic Society3 and the World Health Organization4 recommend that pyrazinamide be given throughout the intensive phase of 6-month short-course chemotherapy and that isoniazid be given in a dose of 900 mg (15 mg/kg) in a twice-weekly protocol.
We support wholeheartedly the authors' decision to add ethambutol to their standard regimen. Our reasons for doing so are not because of concerns for multidrug-resistant tuberculosis but because the 3-drug regimen (isoniazid, rifampin, and pyrazinamide) is not ideal in Haiti, where all existing data suggest that the isoniazid resistance rate is high, especially in those with a history of prior treatment.5–9 In the regimen reported, pyrazinamide would be the only active drug other than rifampin in a patient harboring an isoniazid-resistant isolate, and it is not very effective at protecting against resistance to its companion drug, rifampin.10
These comments derive from a sincere interest in promoting best practice in Haiti. They are not meant to be insensitive to the reality: the grinding poverty that compels estimable public services, such as the Haitian Study Group on Kaposi's Sarcoma and Opportunistic Infections (GHESKIO) in Port-au-Prince, to explore approaches that they might not otherwise explore.
References
1. Desvarieux M, Hyppolite P-R, Johnson WD Jr, Pape JW. A novel approach to directly observed therapy for tuberculosis in an HIV-endemic area. Am J Public Health. 2001;91:138–141.[Abstract]
2. Rieder HL, Arnadottir T, Trébucq D, Enarson DA. Tuberculosis treatment: dangerous regimens? Int J Tuberc Lung Dis.2001;5:1–3.[Medline]
3. American Thoracic Society. Treatment of tuberculosis and tuberculosis infection in adults and children. Am J Respir Crit Care Med.1994;149:1359–1374.[Abstract]
4. Standardized treatment regimens. In: Maher D, Chaulet P, Spinaci S, Harries A, eds. Treatment of Tuberculosis: Guidelines for National Programmes. 2nd ed. Geneva, Switzerland: World Health Organization; 1997:25–31.
5. Pitchenik AE, Russell BW, Cleary T, Pejovic I, Cole C, Snider DE Jr. The prevalence of tuberculosis and drug resistance among Haitians. N Engl J Med. 1982;307:162–165.[Medline]
6. Scalcini M, Carré G, Jean-Baptiste M, et al. Antituberculous drug resistance in central Haiti. Am Rev Respir Dis. 1990;142:508–511.[Medline]
7.
Pablos-Mendez A, Raviglione MC, Laszlo A, et al. Global surveillance for antituberculosis-drug resistance, 1994–1997. N Engl J Med. 1998;338:1641–1649.
8. Long R, Scalcini M. More on the question of optimal chemotherapy in the presence of isoniazid resistance. Int J Tuberc Lung Dis. 2000;4:890–894.[Medline]
9. Ollé-Goig JE, Alvarez J. Treatment of tuberculosis in a rural area of Haiti: directly observed and non-observed regimens. The experience of Hôpital Albert Schweitzer. Int J Tuberc Lung Dis 2001;5:137–141.[Medline]
10. Mitchison DA. The action of antituberculous drugs in short course chemotherapy. Tubercle. 1995;66:219–225.
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
