Tuberculosis (TB) is a disease that is caused by a bacterial infection that affects an estimated two billion people (about a third of the world's population). However, most people have dormant (latent) infections and only a small percentage of people infected with TB will develop an active disease. Preventing latent TB infection (LTBI) developing into active TB, through the use of drugs, is an important part of global TB control. Treatment with the drug isoniazid for six months is recommended, but the treatment period is long, it can cause liver damage, and only about half of the people who start this drug treatment complete it.
The authors of this review evaluated alternatives to isoniazid monotherapy in HIV-negative people with LTBI. They identified 10 randomized controlled trials that included 10,717 adults and children, who were mostly HIV-negative, with a follow-up period ranging from two to five years.
Rifampicin for three to four months may give quite similar results to isoniazid for six months in preventing TB, and may cause fewer side effects. As the treatment period with rifampicin is shorter, it may result in more people completing treatment. Two other drug combination treatments (rifampicin plus isoniazid, and rifampicin plus pyrazinamide) did not differ in preventing TB compared with isoniazid alone, but they resulted in more adverse events. A third combination of rifapentine plus isoniazid supervised weekly for three months was as effective in preventing TB as self-administered isoniazid for nine months, increased treatment completion, and caused less liver toxicity, though treatment-limiting adverse events were more frequent with the weekly rifapentine and isoniazid combination.