Defining effective treatment for latent tuberculosis infection

One of the keys to decreasing the incidence of active tuberculosis (TB) is preventing reactivation by aggressively treating latent TB infection. The American Thoracic Society and the CDC endorse 2 regimens using isoniazid (INH) and 1 regimen using rifampin. A 9-month regimen of INH is optimal for most patients. However, the drug is associated with mild hepatotoxicity and hepatitis. If aminotransferase levels are 3 to 5 times higher than normal or the patient has signs and symptoms such as nausea, vomiting, anorexia, persistently dark urine, jaundice, malaise, unexplained fever for more than 3 days, or right upper quadrant tenderness, INH should be discontinued. A daily dose of rifampin (600 mg in adults and 10 to 20 mg/kg in children) is reserved for persons exposed to patients with INH-resistant and rifampin-sensitive disease.