NCT01258504

Influence of CYP3A4-induction by St. John's Wort on the Steady State Pharmacokinetics of Bosentan

Influence of Cytochrome P450 3A4 (CYP3A4)-Induction by St. John's Wort (SJW) on the Steady State Pharmacokinetics of Bosentan

• Status: Completed
• Phase: —
• Study type: Observational
• Enrollment: 13 (actual)
• Sponsor: Gerd Mikus · Academic / Other
• Sex: All
• Age: 18 Years – 65 Years
• Healthy volunteers: Accepted

Summary

The aim of the present study is to assess the impact of the cytochrome P450 2C9 (CYP2C9) genotype (\*2 and \*3 allele versus wild type; \~3-5% poor metabolisers in Caucasian population) on the pharmacokinetics of bosentan and the impact of CYP3A4-induction by St. John's wort (SJW) on steady state bosentan which is a CYP3A4 inducer itself.

Detailed description

We evaluate the effect of SJW on bosentan pharmacokinetics and its relationship to polymorphisms in the CYP2C9 gene known to reduce CYP2C9 activity. This study will be conducted at bosentan steady-state because concentrations decrease in the first 10 days of treatment due to auto-induction of the metabolism.

Conditions

• Drug Interactions

Interventions

Type	Name	Description
DRUG	St. Johns Wort	* Administration of bosentan: 1 x 125 mg p.o. on days 1 and 20, 2 x 62.5 mg p.o. on day 2, 2 x 125 mg p.o. on days 3-19. * Administration of SJW: 3 x 300 mg daily p.o. on days 11-19 and 2 x 300 mg on day 20

Timeline

• Start date: 2011-01-01
• Primary completion: 2011-12-01
• Completion: 2012-06-01
• First posted: 2010-12-13
• Last updated: 2017-05-31
• Results posted: 2015-06-02

Locations

1 site across 1 country: Germany