Drug approved for rare but dangerous form of TB

FDA Consumer, Sept-Oct, 1998

The first new drug in 25 years to treat the most common form of tuberculosis received accelerated approval by FDA on June 22.

Rifapentine is intended to be used in combination with other anti-tuberculosis drugs to treat pulmonary tuberculosis, a lung infection that can be highly contagious and life-threatening. Rifapentine has been designated an orphan drug because pulmonary tuberculosis affects a relatively small population of patients in the United States.

Despite a higher relapse rate of pulmonary tuberculosis for patients treated with a drug combination that includes rifapentine during clinical trials than those treated with the similar drug rifampin, an agency advisory committee recommended approval because neither relapse rate was alarmingly high and:

* Patients are more likely to take rifapentine correctly because the drug regimen is easier to follow.

* Better compliance not only improves treatment results, but should deter the drug resistance associated with antibiotics.

While using rifapentine, patients and their health-care providers should watch for increased liver enzyme levels, which can lead to liver damage, and increased uric acid levels, which can lead to gout. One of the most common side effects of this drug is discolored, orange-reddish urine.

Marion Merrell Dow, Kansas City, Mo., will manufacture rifapentine under the trade name Priftin.