MAJOR — Use With Caution
FDA-documented CYP2D6 interaction. Paroxetine is the strongest CYP2D6 inhibitor among SSRIs. Use alternative beta-blocker or alternative SSRI.
Evidence level: STRONG
Paxil (paroxetine) is the strongest SSRI blocker of the enzyme that breaks down metoprolol. This can cause metoprolol to build up to dangerous levels, causing your heart to beat too slowly.
Paroxetine is the most potent CYP2D6 inhibitor among SSRIs. Can increase metoprolol levels several-fold. FDA labels acknowledge CYP2D6-mediated interactions.
If taking both, monitor your heart rate regularly. Tell your doctor if your resting heart rate drops below 50 or you feel very fatigued. Switching one medication may be the safest approach.
Take each at their prescribed times. Some SSRIs (fluoxetine, paroxetine) inhibit CYP2D6, which metabolizes metoprolol and propranolol — this can increase beta-blocker levels and cause more pronounced heart rate and blood pressure lowering. Monitor for dizziness or fatigue.
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.
Very slow heartbeat, dizziness, fainting, extreme fatigue, cold extremities, worsening shortness of breath
Switch to atenolol or use a different SSRI (sertraline, citalopram). Monitor heart rate and blood pressure closely.
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 (paroxetine) is the strongest SSRI blocker of the enzyme that breaks down metoprolol. This can cause metoprolol to build up to dangerous levels, causing your heart to beat too slowly.
Take each at their prescribed times. Some SSRIs (fluoxetine, paroxetine) inhibit CYP2D6, which metabolizes metoprolol and propranolol — this can increase beta-blocker levels and cause more pronounced heart rate and blood pressure lowering. Monitor for dizziness or fatigue.
Very slow heartbeat, dizziness, fainting, extreme fatigue, cold extremities, worsening shortness of breath
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 atenolol or use a different SSRI (sertraline, citalopram). Monitor heart rate and blood pressure closely.
Or browse the full interaction database (121,000+ pairs).