Multiple-dose pharmacokinetics, safety, and tolerability of bosentan, an endothelin receptor antagonist, in healthy male volunteers

Article Article scientifique Article Multiple-dose pharmacokinetics, safety, and tolerability of bosentan, an endothelin receptor antagonist, in healthy male volunteers eng 1999 author Weber Claude 25067 author Schmitt R. author Birnboeck H. author Hopfgartner Gerard 0000-0002-9087-606X 31827 author Eggers H. author Meyer Jean-Marc 24981 author van Marle S. author Viischer H W. author Jonkman J H. 703-714 10.1177/00912709922008344 10392325 0091-2700 http://jcp.sagepub.com/cgi/reprint/39/7/703 The multiple-dose pharmacokinetics, safety, and tolerability of oral bosentan, a selective endothelin receptor antagonist, were investigated in healthy male volunteers. In study A, an ascending-dose, double-blind, placebo-controlled trial, doses of 100, 200, 500, and 1000 mg bosentan or placebo were given once daily for 8 days as tablets (100 and 500 mg dose strength). In study B, a double-blind, placebo-controlled trial, 500 mg tablets of bosentan or placebo tablets were given once daily for 8 days with two additional single intravenous dose administrations of 250 mg bosentan 48 hours before the first and 24 hours after the last oral dose. The drug was very well tolerated. No effects on pulse rate, ECGs, or clinical laboratory tests were observed. Marginal effects on blood pressure were seen in subjects only when standing. The oral bioavailability of bosentan was 43% to 48%, with a small interindividual variability of 20%. Doses above 500 mg did not lead to significant further increases in plasma levels of bosentan. From the first to the last day of the oral treatment phase, plasma concentrations of bosentan decreased by 30% to 40% due to a 2-fold increase in plasma clearance. Absorption and plasma protein binding did not change. The 24-hour urinary excretion of 6 beta-hydroxycortisol was increased in parallel by approximately 1.7-fold, indicating induction of cytochrome P450 3A isozymes. The two metabolites of bosentan reached plasma concentrations well below those of bosentan and will most likely not contribute to the pharmacological activity. Administration, Oral Antihypertensive Agents/adverse effects/pharmacokinetics Area Under Curve Blood Pressure/drug effects Diastole Dose-Response Relationship, Drug Double-Blind Method Gastrointestinal Diseases/chemically induced Headache/chemically induced Humans Male Metabolic Clearance Rate Pyrimidines/blood Receptors, Endothelin/antagonists & inhibitors Sulfonamides/adverse effects/blood/metabolism/pharmacokinetics Systole Dewey 500 Dewey 610 Dewey 615 31 Section des sciences pharmaceutiques 17 3 Faculté de médecine 2 false Journal of clinical pharmacology 39 7 b1e13fda-6ae3-41d5-aa7b-56b1a5dd7cae Article (Accepted version) Restricted article.pdf 313315 application/pdf restrictedAccess Faculté des sciences / Section des sciences pharmaceutiques Faculté de médecine

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Multiple-dose pharmacokinetics, safety, and tolerability of bosentan, an endothelin receptor antagonist, in healthy male volunteers	Journal of clinical pharmacology			1999	602	0

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Meyer, Jean-Marc