Treating latent tuberculosis : Efficacy of rifapentine plus isoniazid combination therapy vs. isoniazid monotherapy

Abstract: Latent tuberculosis infection (LTBI) is a global health issue that affects approximately one quarter of the world’s population. It refers to a state of persistent immune response to Mycobacterium tuberculosis without clinical evidence of active tuberculosis (TB). Latent tuberculosis infected individuals are asymptomatic and not contagious to others, however 5-15% of all infected individuals are at risk of developing active tuberculosis and become contagious, severely ill, or worse, die from active TB. There are identified risk groups that are targeted for identification, diagnosis and treatment of latent tuberculosis infection. These are human immunodeficiency virus (HIV) patients, children and adolescents, household or close contacts of active TB cases, migrants, refugees, prisoners and health care workers. The standard treatment used for treating LTBI is the isoniazid monotherapy. It has a high proven efficacy rate but is linked to poor acceptance and low completion rates, basically due to its long treatment duration and poor tolerability. A newer treatment regimen is the rifapentine plus isoniazid combination therapy. It is an effective regimen against LTBI and has a shorter treatment duration. The aim of this literature study was to evaluate the efficacy of rifapentine plus isoniazid combination therapy compared with the isoniazid monotherapy as treatment of latent tuberculosis infection. This thesis was based on five randomized clinical trials collected from PubMed database. The studies should have entailed an efficacy comparison between isoniazid monotherapy and rifapentine plus isoniazid combination therapy for the treatment of patients with latent tuberculosis. The studies showed lower rates of active TB and death in the rifapentine plus isoniazid combination group in comparison with the isoniazid monotherapy. The studies also proved that rifapentine plus isoniazid combination therapy was noninferior to the standard isoniazid monotherapy. The completion rates were significantly higher in the combination therapy arm. The safety profile between the two treatment regimens was similar, but with an increased hepatotoxicity rates in the isoniazid-only arm. The rifapentine plus isoniazid combination therapy is as efficacious as the isoniazid monotherapy. This shorter regimen could be used as first hand therapy as well for latent tuberculosis patients with high-risk of developing active TB as it has shown good tolerability and higher completion rates that is important to successfully treat LTBI and help eliminate TB worldwide.