BACKGROUND: In vitro, bosentan has been shown to be a mild inducer of cytochrome P450 (CYP) 2C9 and 3A4. PURPOSE: To investigate in vivo the mutual pharmacokinetic interactions between bosentan and simvastatin, a CYP3A4 substrate. METHODS:Nine healthy male subjects were treated in a three-period randomised crossover study with: (A) bosentan 125 mg twice daily for 5.5 days; (B) simvastatin 40 mg once daily for 6 days; and (C) bosentan 125 mg twice daily and simvastatin 40 mg once daily for 5.5 and 6 days, respectively. Plasma concentration-time profiles of bosentan and its metabolites (treatments A and C) and simvastatin and beta-hydroxyacid simvastatin (treatments B and C) were determined on day 6. RESULTS: Steady-state conditions for bosentan and its metabolites were attained on day 4 of treatment. The pharmacokinetic parameters of bosentan and its metabolites were not influenced by concomitant treatment with simvastatin: areas under the plasma concentration-time curve over one administration interval of 12 hours (AUC(tau)) [geometric mean and 95% CI] were 4586 (3719-5656) and 4928 (3945-6156) micro g * h/L. In contrast, bosentan significantly reduced exposure to simvastatin and beta-hydroxyacid simvastatin by 34 and 46%, respectively. AUC(tau) values for simvastatin were 30.5 (23.1-40.2) and 20.0 (15.9-25.1) micro g * h/L and for beta-hydroxyacid simvastatin 43.0 (32.1-57.8) and 23.4 (16.7-32.6) micro g * h/L in treatments B and C, respectively. CONCLUSIONS: Concomitant treatment with bosentan reduces the exposure to simvastatin and beta-hydroxyacid simvastatin by approximately 40%, indicating that in vivo bosentan is also a mild inducer of CYP3A4.
RCT Entities:
BACKGROUND: In vitro, bosentan has been shown to be a mild inducer of cytochrome P450 (CYP) 2C9 and 3A4. PURPOSE: To investigate in vivo the mutual pharmacokinetic interactions between bosentan and simvastatin, a CYP3A4 substrate. METHODS: Nine healthy male subjects were treated in a three-period randomised crossover study with: (A) bosentan 125 mg twice daily for 5.5 days; (B) simvastatin 40 mg once daily for 6 days; and (C) bosentan 125 mg twice daily and simvastatin 40 mg once daily for 5.5 and 6 days, respectively. Plasma concentration-time profiles of bosentan and its metabolites (treatments A and C) and simvastatin and beta-hydroxyacidsimvastatin (treatments B and C) were determined on day 6. RESULTS: Steady-state conditions for bosentan and its metabolites were attained on day 4 of treatment. The pharmacokinetic parameters of bosentan and its metabolites were not influenced by concomitant treatment with simvastatin: areas under the plasma concentration-time curve over one administration interval of 12 hours (AUC(tau)) [geometric mean and 95% CI] were 4586 (3719-5656) and 4928 (3945-6156) micro g * h/L. In contrast, bosentan significantly reduced exposure to simvastatin and beta-hydroxyacidsimvastatin by 34 and 46%, respectively. AUC(tau) values for simvastatin were 30.5 (23.1-40.2) and 20.0 (15.9-25.1) micro g * h/L and for beta-hydroxyacidsimvastatin 43.0 (32.1-57.8) and 23.4 (16.7-32.6) micro g * h/L in treatments B and C, respectively. CONCLUSIONS: Concomitant treatment with bosentan reduces the exposure to simvastatin and beta-hydroxyacidsimvastatin by approximately 40%, indicating that in vivo bosentan is also a mild inducer of CYP3A4.
Authors: C Weber; R Schmitt; H Birnboeck; G Hopfgartner; H Eggers; J Meyer; S van Marle; H W Viischer; J H Jonkman Journal: J Clin Pharmacol Date: 1999-07 Impact factor: 3.126
Authors: T Prueksaritanont; J M Vega; J D Rogers; K Gagliano; H E Greenberg; L Gillen; M J Brucker; D McLoughlin; P H Wong; S A Waldman Journal: J Clin Pharmacol Date: 2000-11 Impact factor: 3.126
Authors: W Kiowski; G Sütsch; P Hunziker; P Müller; J Kim; E Oechslin; R Schmitt; R Jones; O Bertel Journal: Lancet Date: 1995-09-16 Impact factor: 79.321
Authors: Martin R Wilkins; Omar Ali; William Bradlow; John Wharton; Anne Taegtmeyer; Christopher J Rhodes; Hossein A Ghofrani; Luke Howard; Petros Nihoyannopoulos; Raad H Mohiaddin; J Simon R Gibbs Journal: Am J Respir Crit Care Med Date: 2010-05-15 Impact factor: 21.405