Antidepressants with Minimal CYP2D6-Mediated Interaction Risk with Metoprolol
Metoprolol is metabolized primarily by CYP2D6, and concomitant use with potent CYP2D6-inhibiting antidepressants can increase metoprolol exposure and reduce cardioselectivity (Class/Level not stated in labeling). [1], [2] Based on product-label interaction data, co-prescription without clinically significant effects on blood pressure or heart rate is demonstrated for citalopram and escitalopram when given with metoprolol. [3], [4]
Interaction Mechanism Relevant to Metoprolol
Metoprolol plasma concentrations can increase when CYP2D6 is inhibited, which can mimic the pharmacokinetics of CYP2D6 poor metabolizer status and reduce cardioselectivity. [1], [2]
Antidepressants Demonstrated to Have No Clinically Significant Effects on Metoprolol Hemodynamics
- Citalopram (coadministration with metoprolol had no clinically significant effects on blood pressure or heart rate). [3]
- Escitalopram (coadministration with metoprolol had no clinically significant effects on blood pressure or heart rate). [4]
Antidepressants Considered Clinically Significant CYP2D6 Inhibitors with Metoprolol
The following antidepressants are identified as clinically significant potent CYP2D6 inhibitors in metoprolol labeling and are therefore associated with clinically meaningful interaction risk:
- Fluvoxamine. [1], [2]
- Fluoxetine. [1], [2]
- Paroxetine. [1], [2]
- Sertraline. [1], [2]
- Bupropion. [1], [2]
- Clomipramine. [1], [2]
- Desipramine. [1], [2]
Initiation and Monitoring Considerations
When a potent CYP2D6-inhibiting antidepressant cannot be avoided, metoprolol labeling recommends close monitoring because increased metoprolol blood levels can decrease cardioselectivity. [2]
Common Pitfalls to Avoid
- Avoiding the metoprolol–antidepressant interaction screening step can lead to co-prescription with potent CYP2D6 inhibitors, which increases metoprolol exposure. [1], [2]
- Assuming that all SSRIs or SNRIs have minimal interaction potential with metoprolol can lead to clinically significant CYP2D6-mediated interactions because several antidepressants are categorized as potent CYP2D6 inhibitors in metoprolol labeling. [1], [2]
Targets and Goals of Therapy
No antidepressant-specific BP/HR target is established for co-prescribing with metoprolol. The metoprolol interaction risk assessment focuses on avoiding or monitoring clinically significant CYP2D6-mediated increases in metoprolol exposure. [1], [2]