Impacts of 12-dose regimen for latent tuberculosis infection

Treatment of latent tuberculosis infection (LTBI) is essential for eradicating tuberculosis (TB). Moreover, the patient adherence is crucial in determining the effectiveness of TB control. Isoniazid given by DOTS daily for 9 months (9H) is the standard treatment for LTBI in Taiwan. However, the completion rate is low due to the long treatment period and its side effects. The combined regimen using a high dose of rifapentine/isoniazid once weekly for 12 weeks (3HP) has been used as an alternative treatment option for LTBI in the United States. This may result in a higher completion rate. In this pilot study, patient adherence and cost of these 2 treatment regimens were investigated. Thus, we aimed to assess the treatment completion rate and costs of 3HP and compare to those with 9H.Data from 691 cases of LTBI treatments including 590 cases using the conventional regimen and 101 cases with rifapentine/Isoniazid were collected. The cost was the sum of the cost of treatment with Isoniazid for 9 months or with rifapentin/Isoniazid for 3 months of all contacts. The effectiveness was the cost of cases of tuberculosis avoided.In this study, the treatment completion rate for patients prescribed with the 3 months rifapentine/isoniazid regimen (97.03%) was higher than those given the conventional 9-month isoniazid regimen (87.29%) (P <0.001). The cost of 3HP and 9H was US$261.24 and US$717.3, respectively. The cost-effectiveness ratio with isoniazid for 9 months was US$ 15392/avoided 1 case of tuberculosis and US$ 5225/avoided 1 case of tuberculosis with 3HP. In addition, when compared with the conventional regimen, there were fewer patients discontinued with rifapentine/isoniazid regimen due to undesirable side effects.This was the first study to compare the 2 treatment regimens in Taiwan, and it showed that a short-term high-dosage rifapentine/isoniazid treatment regimen reduced costs and resulted in higher treatment completion than the standard LTBI isoniazid treatment.