Venlafaxine Interactions

Venlafaxine is a serotonin-norepinephrine reuptake inhibitor (SNRI). St. John's wort independently inhibits serotonin (and to a lesser extent norepinephrine and dopamine) reuptake. Combining them can drive a sharp rise in synaptic serotonin and trigger serotonin syndrome, and St. John's wort can also alter venlafaxine pharmacokinetics through CYP3A4 induction.

Venlafaxine (Effexor) is an SNRI that, like other antidepressants, has additive CNS-depressant effects with alcohol. The FDA-approved label warns patients to avoid alcohol because of worsening drowsiness, dizziness, impaired judgment, and the potential to aggravate the underlying mood or anxiety disorder.