Isoniazid preventive therapy and risk for resistant tuberculosis.
In the context of tuberculosis (TB) resurgence, isoniazid preventive therapy (IPT) is increasingly promoted, but concerns about the risk for development of isoniazid-resistant tuberculosis may hinder its widespread implementation. We conducted a systematic review of data published since 1951 to assess the effect of primary IPT on the risk for isoniazid-resistant TB. Different definitions of isoniazid resistance were used, which affected summary effect estimates; we report the most consistent results. When all 13 studies (N = 18,095 persons in isoniazid groups and N = 17,985 persons in control groups) were combined, the summary relative risk for resistance was 1.45 (95% confidence interval 0.85-2.47). Results were similar when studies of HIV-uninfected and HIV-infected persons were considered separately. Analyses were limited by small numbers and incomplete testing of isolates, but findings do not exclude an increased risk for isoniazid-resistant TB after IPT. The diagnosis of active TB should be excluded before IPT. Continued surveillance for isoniazid resistance is essential.
Balcells
Maria Elvira
ME
Clinical Research Unit, Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London, United Kingdom.
Thomas
Sara L
SL
Godfrey-Faussett
Peter
P
Grant
Alison D
AD
D000995:Antitubercular Agents / Q000494:pharmacology / Q000627:therapeutic use*; D024881:Drug Resistance, Bacterial; D006801:Humans; D015994:Incidence; D007538:Isoniazid / Q000494:pharmacology / Q000627:therapeutic use*; D009169:Mycobacterium tuberculosis / Q000187:drug effects*; D018570:Risk Assessment; D012307:Risk Factors; D014376:Tuberculosis / Q000188:drug therapy / Q000453:epidemiology / Q000517:prevention & control*; D018088:Tuberculosis, Multidrug-Resistant / Q000453:epidemiology / Q000517:prevention & control
D000995:Antitubercular Agents; D007538:Isoniazid