Drug Groups

approved

Description

Rifapentine is an antibiotic drug used in the treatment of tuberculosis. It inhibits DNA-dependent RNA polymerase activity in susceptible cells. Specifically, it interacts with bacterial RNA polymerase but does not inhibit the mammalian enzyme.

Indication

For the treatment of pulmonary tuberculosis.

Pharmacology

Rifapentine is an antibiotic that inhibits DNA-dependent RNA polymerase activity in susceptible cells. Specifically, it interacts with bacterial RNA polymerase but does not inhibit the mammalian enzyme. It is bactericidal and has a very broad spectrum of activity against most gram-positive and gram-negative organisms (including Pseudomonas aeruginosa) and specifically Mycobacterium tuberculosis. Because of rapid emergence of resistant bacteria, use is restricted to treatment of mycobacterial infections and a few other indications. Rifampin is well absorbed when taken orally and is distributed widely in body tissues and fluids, including the CSF. It is metabolized in the liver and eliminated in bile and, to a much lesser extent, in urine, but dose adjustments are unnecessary with renal insufficiency.

Affected Organisms

Biotransformation

Hepatic

Absorption

Rapidly and well absorbed from the gastrointestinal tract.

Protein Binding

97.7% (bound to plasma proteins)

Elimination

Following a single 600 mg oral dose of radiolabeled rifapentine to healthy volunteers (n=4), 87% of the total 14C rifapentine was recovered in the urine (17%) and feces (70%).

Distribution

* 70.2 ± 9.1 L

Clearance

* Apparent Oral cl=2.51 +/- 0.14 L/h [Male tuberculosis patients who received 600 mg rifapentine in combination with isoniazid, pyrazinamide and ethambutol]
* Apparent Oral cl=1.69 +/- 0.41 L/h [Female tuberculosis patients who received 600 mg rifapentine in combination with isoniazid, pyrazinamide and ethambutol]

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