Major
Clopidogrel × fluvoxamine
Antiplatelet agents – P2Y12 receptor inhibitors×SSRI
Mechanism
Clopidogrel is a prodrug, activated by CYP2C19. Fluvoxamine is a potent CYP2C19 inhibitor. The active clopidogrel metabolite is not formed and antiplatelet effect is lost.
Symptoms
The patient feels no symptoms – the weakened antiplatelet effect is silent. The combination raises recurrent myocardial infarction, stent thrombosis, and stroke risks.
Management
The combination is not prescribed. Alternative antidepressants without CYP2C19 effect: sertraline or escitalopram (moderate but weaker effect), or mirtazapine/agomelatine (no effect). Alternative antiplatelet: ticagrelor (not CYP2C19-dependent).