Send to

Choose Destination
See comment in PubMed Commons below
Br J Clin Pharmacol. 1995 Nov;40(5):481-5.

The effects of selective serotonin reuptake inhibitors and their metabolites on S-mephenytoin 4'-hydroxylase activity in human liver microsomes.

Author information

Department of Clinical Pharmacy, Showa University, Tokyo, Japan.


The inhibitory effects of four selective serotonin reuptake inhibitors (SSRIs), fluoxetine, sertraline, paroxetine and citalopram, and three metabolites (norfluoxetine, demethylcitalopram and didemethylcitalopram), on S-mephenytoin 4'-hydroxylation activities in human liver microsomes were studied. The 4'-hydroxylation of S-mephenytoin, a representative substrate toward CYP2C19, was competitively inhibited by all the SSRIs and their metabolites studied. The mean Ki values of fluoxetine, norfluoxetine, sertraline, paroxetine, citalopram, demethylcitalopram and didemethylcitalopram were 5.2, 1.1, 2.0, 7.5, 87.3, 55.8 and 7.7 microM, respectively. The findings suggest that some SSRIs and their metabolites with a low Ki value (e.g., fluoxetine, norfluoxetine) may reduce the clearance of drugs metabolized by this isoform of P450, thereby resulting in a possible drug-drug interaction, when administered simultaneously. In addition, SSRIs and their metabolites examined herein may be substrates toward CYP2C19.

[Indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons


    Supplemental Content

    Full text links

    Icon for Wiley Icon for PubMed Central
    Loading ...
    Support Center