Reports
Clinical Pharmacology & Therapeutics (2009); 85, 3, 273–276 doi:10.1038/clpt.2008.213
Interindividual Variation in the Pharmacokinetics of 
9-Tetrahydrocannabinol as Related to Genetic Polymorphisms in CYP2C9
C Sachse-Seeboth1, J Pfeil1, D Sehrt1, I Meineke1, M Tzvetkov1, E Bruns1, W Poser2, SV Vormfelde1 and J Brockmöller1
- 1Department of Clinical Pharmacology, University Medicine, Göttingen, Germany
- 2Department of Psychiatry and Psychotherapy, University Medicine, Göttingen, Germany
Correspondence: J Brockmöller, (jbrockm@gwdg.de)
Received 18 May 2008; Accepted 16 September 2008; Published online 12 November 2008.
Abstract
The impact of the CYP2C9 polymorphism on the pharmacokinetics of orally administered 
9-tetrahydrocannabinol (THC) was studied in 43 healthy volunteers. THC pharmacokinetics did not differ by CYP2C9*2 allele status. However, the median area under the curve of THC was threefold higher and that of 11-nor-9-carboxy-9-tetrahydrocannabinol was 70% lower in CYP2C9*3/*3 homozygotes than in CYP2C9*1/*1 homozygotes. CYP2C9*3 carriers also showed a trend toward increased sedation following administration of THC. Therefore, the CYP2C9*3 variant may influence both the therapeutic and adverse effects of THC.
