title: Isoniazid preventive therapy and risk for resistant tuberculosis.
abstract: 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.
authors.affiliation: Clinical Research Unit, Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London, United Kingdom.
authors.forename: Maria Elvira
authors.initials: ME
authors.lastname: Balcells
authors.forename: Sara L
authors.initials: SL
authors.lastname: Thomas
authors.forename: Peter
authors.initials: P
authors.lastname: Godfrey-Faussett
authors.forename: Alison D
authors.initials: AD
authors.lastname: Grant
mesh_terms: 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
chemical_list: D000995:Antitubercular Agents; D007538:Isoniazid