drug interaction(s) of tamoxifen with SSRI

Drug interactions

• CYP2D6-mediated conversion of tamoxifen is inhibited by CYP2D6 inhibitors, including SSRIs paroxetine, fluoxetine, & sertraline
• apparently, citalopram, escitalopram, & fluvoxamine are weaker CYP2D6 inhibitors & their interactions may not be clinically significant
• paroxetine does inhibit benefit of tamoxifen in women with breast cancer
• increased mortality from breast cancer in women taking both tamoxifen & paroxetine relative to tamoxifen alone
• fluoxetine was not found to be associated with an increase in mortality, possibly because the number of women taking both fluoxetine & tamoxifen was low

More general terms

• drug interaction