Interactions between fluoxetine and Astemizole (astemizole)
fluoxetine and astemizole (Major Drug-Drug)
GENERALLY AVOID: Theoretical concerns and one case report have suggested that coadministration of fluoxetine and terfenadine or astemizole may be associated with cardiotoxic effects, including prolongation of the QT interval. The mechanism probably is related to the inhibition of terfenadine and astemizole metabolism by fluoxetine or norfluoxetine, which is a potent inhibitor of CYP450 3A4. Other selective serotonin reuptake inhibitors (SSRIs) may interact with terfenadine and astemizole in a similar manner.
MANAGEMENT: If terfenadine or astemizole must be used with an SSRI, caution and close observation for evidence of cardiotoxicity are recommended.
