Reference

Pharmacokinetics of rifapentine, a new long lasting rifamycin, in the rat, the mouse and the rabbit

Pharmacokinetics of rifapentine, a new long lasting rifamycin, in the rat, the mouse and the rabbit. Assandri, Alessandro; Ratti, Bruno; Cristina, Tito (Res. Lab., Gruppo Lepetit S.p.A., Milan 38-20158, Italy). J. Antibiot., 37(9), 1066-75 (English) 1984. CODEN: JANTAJ. ISSN: 0021-8820. DOCUMENT TYPE: Journal CA Section: 1 (Pharmacology) A study on the pharmacokinetics of rifapentine (I) [61379-65-5], a new long-lasting rifamycin, has been carried out in the rat, the mouse, and the rabbit. The investigation was made using either radioactive or unlabeled rifapentine and both the total 14C and the unchanged compd. were assayed. In the rat, the overall evidence obtained was: (a) the oral absorption of rifapentine into central compartment, due to its poor water soly., appears to be dose-dependent with a satisfactory oral absorption (84%) after a dose of 3 mg/kg, lower (65%) after 10 mg/kg; (b) the antibiotic undergoes rapid liver uptake while it diffuses into the tissue compartment more slowly, with particular affinity for the adrenals, pancreas and kidneys; concns. higher than in plasma were also measured in the lungs; (c) elimination of rifapentine from the blood and tissue compartments suggests a non-linear capacity-limited kinetics where the terminal elimination phase has a monoexponential course. The terminal plasma half-life ranged between 14 and 18 h; the compd. is eliminated mainly via the bile with the feces (92% of dose). In mice rifapentine shows a kinetic profile resembling that obtained in rats, whereas in rabbits, it is metabolized and/or eliminated much more rapidly with a half-life of only 1.8 h.

Rifabutin and rifapentine compared with rifampin against Mycobacterium leprae in mice

Rifabutin and rifapentine compared with rifampin against Mycobacterium leprae in mice. Pattyn, Stefaan R. (Inst. Trop. Med., Univ. Antwerpen, Antwerp, Belg.). Antimicrob. Agents Chemother., 31(1), 134 (English) 1987. CODEN: AMACCQ. ISSN: 0066-4804. DOCUMENT TYPE: Journal CA Section: 1 (Pharmacology) In mice with infection from M. leprae, single doses of the new rifamide derivs. rifabutin [72559-06-9] and rifapentine [61379-65-5] were 8-times more potent than rifampin in eradicating the pathogen; the min. EDs of rifabutin and rifapentine were 2.5 and <5 mg/kg, resp.