Venlafaxine is an SNRI used for depression, generalised anxiety disorder, and neuropathic pain.
Also known as: venlafaxine, effexor
SNRI + CYP3A4 inhibitor: venlafaxine levels may increase.
Venlafaxine is metabolised by CYP2D6 (active desvenlafaxine) and CYP3A4. Ritonavir inhibits CYP3A4. Co-administration may increase venlafaxine levels 1.5-2-fold. Additional risk: venlafaxine may cause dose-dependent hypertension (>150 mg/day), and elevated levels increase this risk. Monitor blood pressure and serotonergic signs. Reduce venlafaxine dose if necessary.
SNRI + CYP3A4 inhibitor: ritonavir may increase venlafaxine levels. Risk of hypertension and serotonin syndrome.
Ritonavir inhibits CYP3A4, one of the metabolic pathways for venlafaxine. The effect is moderate but relevant.
BP, serotonergic signs.
Hypertensive crisis, serotonin syndrome.
Monitor for serotonergic signs and hypertension.
DailyMed/FDA
No documented food or drink interactions.
No documented disease interactions.
No documented pregnancy or breastfeeding information.
Clinical and educational support tool. The information does not replace a medical prescription or the opinion of a qualified healthcare professional.
SNRI: inhibits serotonin (low doses) and noradrenaline (high doses) reuptake.
SERT inhibition (doses ≥75 mg) and NERT inhibition (doses ≥150 mg). No anticholinergic, antihistaminic or α1 activity.
Complete oral absorption. Bioavailability: 40-45%.
Metabolised by CYP2D6 to O-desmethylvenlafaxine (active, dominant metabolite).
5-11 h (venlafaxine); 11-13 h (O-desmethylvenlafaxine).
Medicines from the same therapeutic group (ATC classification) or the same pharmacological class.
