MAJOR — Use With Caution
FDA-documented interaction. Paroxetine is the most potent CYP2D6 inhibitor among SSRIs. Use alternative SSRI.
Evidence level: STRONG
Paxil is the SSRI most likely to dangerously increase flecainide levels because it is the strongest blocker of the enzyme that breaks down flecainide. This can cause the heart rhythm medication to become toxic.
Paroxetine is the strongest CYP2D6 inhibitor among SSRIs. Flecainide is a CYP2D6 substrate. Significantly increased flecainide levels with pro-arrhythmic risk.
Do not take Paxil with flecainide if possible. Ask about sertraline, citalopram, or escitalopram as alternatives — they have much less effect on flecainide metabolism.
Take Paroxetine at the same time each day — morning is most common to avoid sleep disruption. Flecainide follows its prescribed schedule. SSRIs have a long half-life, so consistency matters more than the exact hour.
Higher risk for: elderly, those on multiple serotonergic drugs, people with liver impairment, CYP2D6 poor metabolizers, recent dose changes, or concurrent use of MAOIs or triptans.
Palpitations, dizziness, visual changes, worsening heart rhythm, fainting
Switch to SSRI with minimal CYP2D6 inhibition. Monitor flecainide levels if combination is unavoidable.
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.
Paxil is the SSRI most likely to dangerously increase flecainide levels because it is the strongest blocker of the enzyme that breaks down flecainide. This can cause the heart rhythm medication to become toxic.
Take Paroxetine at the same time each day — morning is most common to avoid sleep disruption. Flecainide follows its prescribed schedule. SSRIs have a long half-life, so consistency matters more than the exact hour.
Palpitations, dizziness, visual changes, worsening heart rhythm, fainting
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.
Switch to SSRI with minimal CYP2D6 inhibition. Monitor flecainide levels if combination is unavoidable.
Or browse the full interaction database (121,000+ pairs).