MAJOR — Use With Caution
DANGEROUS — fluoxetine is the worst SSRI to combine with TCAs due to potent CYP2D6 inhibition
Evidence level: STRONG
Prozac dramatically increases amitriptyline levels — one of the most dangerous SSRI-TCA combinations.
Fluoxetine is a potent CYP2D6 inhibitor. Can increase amitriptyline levels 3-5x. Plus dual serotonergic risk.
Generally avoid. If used, reduce amitriptyline dose by 75% and monitor levels closely. Fluoxetine effects persist weeks after stopping.
Take Fluoxetine at the same time each day — morning is most common to avoid sleep disruption. Amitriptyline follows its prescribed schedule. SSRIs have a long half-life, so consistency matters more than the exact hour.
Cardiac disease, CYP2D6 poor metabolizers, elderly
Cardiac arrhythmias, seizures, severe anticholinergic effects, serotonin syndrome, QT prolongation
This combination requires intensive monitoring. Consider alternative approaches.
Discuss this combination with your prescriber. They may adjust timing, dosing, or switch to an alternative with fewer interaction risks. Never stop an antidepressant abruptly — taper under medical guidance.
Prozac dramatically increases amitriptyline levels — one of the most dangerous SSRI-TCA combinations.
Take Fluoxetine at the same time each day — morning is most common to avoid sleep disruption. Amitriptyline follows its prescribed schedule. SSRIs have a long half-life, so consistency matters more than the exact hour.
Cardiac arrhythmias, seizures, severe anticholinergic effects, serotonin syndrome, QT prolongation
Discuss this combination with your prescriber. They may adjust timing, dosing, or switch to an alternative with fewer interaction risks. Never stop an antidepressant abruptly — taper under medical guidance.
This combination requires intensive monitoring. Consider alternative approaches.
Or browse the full interaction database (121,000+ pairs).