Does Trazodone Lower Heart Rate?
Trazodone tends to lower heart rate, though this effect is modest and not its primary cardiovascular action. 1
Cardiovascular Effects on Heart Rate
Trazodone produces a tendency to lower heart rate in depressed cardiac patients, distinguishing it from many other antidepressants that typically cause tachycardia. 1
The heart rate reduction is generally mild and clinically insignificant in most patients at therapeutic doses. 1
This bradycardic tendency contrasts with tricyclic antidepressants, which commonly cause reflex tachycardia as a compensatory response to their hypotensive effects. 2
Context of Other Cardiovascular Effects
While trazodone may lower heart rate, its more prominent cardiovascular effects include:
Orthostatic hypotension is the most common cardiovascular side effect, though trazodone produces less postural hypotension than most tricyclic antidepressants. 3, 1
Trazodone has minimal effects on cardiac conduction at therapeutic doses and does not worsen supraventricular arrhythmias. 1
The American Heart Association notes that in overdose situations, trazodone can cause serious arrhythmias including QTc prolongation and torsades de pointes, though these are rare at therapeutic doses. 4, 5
Clinical Implications for Cardiac Patients
Lower doses (100-300 mg) are better tolerated in patients with significant cardiovascular disease and are more effective than higher doses in this population. 1
The American College of Cardiology recommends baseline ECG before initiating trazodone in patients with cardiac risk factors, with follow-up ECG within 30 days for high-risk patients. 4
Caution is warranted in patients with premature ventricular contractions, as there have been case reports of increased ventricular irritability, though this may represent a statistical artifact requiring further research. 6, 1
Comparison to Other Sedating Agents
In the context of cardiovascular intensive care, benzodiazepines show variable chronotropic effects with no clear consensus, while propofol causes bradycardia via muscarinic-receptor activation. 7 Trazodone's mild heart rate-lowering effect positions it as relatively neutral compared to these agents.
Practical Recommendations
The heart rate-lowering effect of trazodone is not clinically significant enough to use the drug specifically for heart rate control. 1
Monitor for orthostatic hypotension more vigilantly than for bradycardia when initiating trazodone. 3, 1
In patients requiring both antidepressant therapy and heart rate control, the modest bradycardic effect may be a minor benefit but should not drive prescribing decisions. 1