Objectives: The recommended treatment for latent tuberculosis infection is isoniazid for 9 months, but this regimen has a low completion rate. The authors wanted to compare treatment with isoniazid and treatment with isoniazid and rifampin in the typical public health setting in a large diverse state and recover as much information as possible from a state database.
Methods: Patients who received latent tuberculosis infection treatment were identified in the Texas Department of State Health Services database for the years 1995-2002. Treatment completion, adverse reactions, and disease development were recorded. Results were analyzed using logistic regression to predict disease development.
Results: In sum, 50 578 patients received isoniazid, and 280 received isoniazid/rifampin. Sixty-one percent of the isoniazid group and 54% of the isoniazid/rifampin group completed treatment. Eighteen percent of the isoniazid/rifampin group possibly had adverse reactions and discontinued treatment; 3% of the isoniazid group discontinued therapy because of side effects. More than 70% of patients with adverse reactions in the isoniazid/rifampin group took the treatment for more than 4 months. Overall, 168 patients in the isoniazid group with a normal chest X-ray and a positive skin test developed tuberculosis during follow-up to 2008; no patients in the isoniazid/rifampin group who had a normal X-ray and completed chemoprophylaxis developed tuberculosis during follow-up.
Conclusions: The isoniazid/rifampin regimen appears to be as effective as the isoniazid regimen. However, completion rates on combination therapy were slightly lower. This regimen needs more formal clinical study since it has the potential to decrease administrative costs and improve completion rates. In addition, state departments of health need to develop networks using community-based resources to reach patients and increase completion rates.
Keywords: community; compliance; drug completion; isoniazid; latent tuberculosis infection; rifampin.