amitriptyline + fluoxetine

Amitriptyline + fluoxetine is a combination of two antidepressant medications, each with distinct mechanisms of action. Amitriptyline is a tricyclic antidepressant (TCA) that primarily inhibits the reuptake of norepinephrine and serotonin, increasing their levels in the central nervous system. Fluoxetine is a selective serotonin reuptake inhibitor (SSRI) that selectively blocks the reuptake of serotonin, enhancing serotonergic neurotransmission. This combination has been used off-label for treatment-resistant depression but carries significant risk due to pharmacokinetic interactions—fluoxetine inhibits CYP2D6, which metabolizes amitriptyline, leading to increased plasma concentrations and potential toxicity. The use of this combination requires careful monitoring due to risks such as serotonin syndrome and cardiac toxicity[3][4][7][9].