Moderate
Probable
Description
Carbamazepine significantly reduces venlafaxine plasma concentrations through CYP3A4 induction, potentially reducing antidepressant efficacy.
Mechanism
Carbamazepine induces CYP3A4 and CYP2C19, which are involved in venlafaxine metabolism, accelerating its clearance and reducing plasma levels.
Clinical Significance
Sub-therapeutic venlafaxine levels may lead to depression relapse or inadequate pain control in patients using it for neuropathic pain.
Management
Monitor clinical response; venlafaxine dose increase may be required; consider an antidepressant less affected by CYP3A4 induction.