Rifampicin plus pyrazinamide versus isoniazid for treating latent tuberculosis infection: a meta-analysis

SETTING: Six trials from Haiti, Mexico, the USA, Brazil, Spain, Zambia and Hong Kong. OBJECTIVE: To evaluate the efficacy and safety of rifampicin plus pyrazinamide (RZ) vs. isoniazid (INH) for the prevention of tuberculosis (TB) among persons with or without human immunodeficiency virus (HIV) infection. DESIGN: Meta-analysis of randomised controlled trials (RCTs) and quasi-RCTs that compared RZ for 2-3 months with INH for 6-12 months. Endpoints were development of active TB, severe adverse effects and death. Treatment effects were summarised as risk difference (RD) with 95 % confidence intervals (0). RESULTS: Three trials conducted in HIV-infected patients and three trials conducted in non-HIV-infected persons were identified. The rates of TB; in the RZ group were similar to those in the INH group, whether the subjects were HIV-infected or not (HIV-infected patients: pooled RD = 0%, 95 % CI - 1-2, P = 0.89; non-HIV-infected persons: pooled RD = 0%, 95% CI -2-1, P = 0.55). There was no difference in mortality between the two treatment groups (HIV-infected patients: pooled RD = -1%, 95% CI -4-2, P = 0.53; non-HIV-infected persons: pooled RD = 0%, 95% CI -1-1, P = 1.00). However, both subgroup analyses showed that a higher incidence of all severe adverse events was associated with 2RZ than INH among non-HIV-infected persons (RD = 29%, 95% CI 13-46, P = 0.0005 vs. RD = 7%, 95% CI 4-10, P < 0.0001). CONCLUSION: RZ is equivalent to INH in terms of efficacy and mortality in the treatment of latent tuberculosis infection. However, this regimen increases the risk of severe adverse effects compared with INH in non-HIV-infected persons.