- Design
- Scoping review, 1990-2025
- Population
- 48 articles on adults taking a beta-blocker with an SSRI
- Primary outcome
- Reported adverse events
- Effect
- Bradycardia most reported (11 articles); CYP2D6 the usual proposed mechanism
A scoping review searched 1990 to 2025 for adverse events in adults taking a beta-blocker and an SSRI together, a common pairing in anxiety and in cardiac patients with depression. It included 48 articles, mostly interventional studies and case reports.
Bradycardia was the most frequently reported problem, mainly in case reports of metoprolol with fluoxetine, paroxetine or sertraline, and propranolol with fluoxetine. Half the studies that examined blood pressure found changes, including hypotension. Where a mechanism was offered, it was usually inhibition of CYP2D6, the enzyme that clears metoprolol and propranolol, by fluoxetine and paroxetine. There were also four reports of self-poisoning with the combination.
These are signals, not measured risks: case reports cannot say how often this happens. But the pharmacology is consistent, and the fix is simple. Where both drugs are needed, pairing choices that avoid strong CYP2D6 inhibition reduces the chance of an interaction.
- Consider an SSRI with little CYP2D6 inhibition, such as citalopram or escitalopram, in patients on metoprolol or propranolol.
- Alternatively, consider a beta-blocker not dependent on CYP2D6, such as bisoprolol or atenolol.
- Check pulse and blood pressure after starting fluoxetine or paroxetine in someone on metoprolol.
- Ask about dizziness, fatigue or fainting after either drug is started.
- Remember that fluoxetine's inhibition persists for weeks after stopping.
Why it matters
The combination is common, and a slow pulse after an antidepressant is easily put down to the beta-blocker alone.
Don't overread it
Mostly case reports; the review cannot estimate how often the interaction causes harm.
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