Background: Tuberculosis is common in drug users, although compliance with therapy may be difficult in this population.
Objective: To evaluate an approach to enhancing compliance with tuberculosis chemoprophylaxis in drug users enrolled on methadone maintenance utilizing an isoniazid (INH)-methadone admixture.
Design: A prospective cohort study.
Setting: A drug treatment program in New Haven, Connecticut, USA.
Patients: Opioid-dependent drug users enrolled in methadone maintenance.
Intervention: Liquid isoniazid was mixed into subjects' daily dose of methadone. Vitamin B6 was given to subjects for self-administration.
Measurements and main results: Number of eligible subjects, reasons for not starting therapy, number starting therapy, proportion completing therapy and median duration of INH therapy were calculated. Thirty-nine subjects were eligible for INH chemoprophylaxis: 34 (87%) received INH mixed directly in their methadone and five (13%) had their INH consumption supervised by a nurse. Among these subjects, 72% (28/39) completed therapy. Among the 11 subjects who discontinued INH, discharge from the methadone maintenance program was the most common reason--73% (8/11). Thus, among the 31 subjects who were not discharged from methadone maintenance, 90% (28/31) successfully completed INH prophylaxis. The median duration of therapy was 182 days.
Conclusions: Tuberculosis chemoprophylaxis using a liquid isoniazid-methadone admixture appears to be an effective approach to enhancing compliance with this therapy in methadone-maintained drug users.