Background: Cardiovascular side effects from antidepressant drugs, including clinically significant blood pressure changes, conduction disturbances, and arrhythmias may complicate long-term therapy. Cardiovascular effects are most common with tricyclic antidepressants, but occur rarely with most antidepressants. Venlafaxine is a unique antidepressant with a broad spectrum of antidepressant activity and a safety profile that resembles serotonin selective reuptake inhibitors.
Method: A MEDLINE search of the literature in the English language for the past 15 years was conducted, and the venlafaxine new drug application data base was reviewed.
Results: Clinically significant conduction abnormalities or arrhythmias have not been reported with venlafaxine; however, this drug has not been studied in patients with underlying cardiovascular disease. A dose-related increase in mean blood pressure has been observed. In placebo-controlled studies with venlafaxine, clinically significant increases in blood pressure (increase in diastolic blood pressure of > or = 15 mm Hg and to > or = 105 mm Hg from baseline) were observed in 5.5% of patients at doses above 200 mg daily. The mean increase in diastolic blood pressure was 7 mm Hg after 6 weeks of treatment with doses of 300 to 375 mg daily. In comparative trials, the overall incidence of clinically significant blood pressure increases with venlafaxine was similar to that of tricyclic antidepressants.
Conclusion: Overall, venlafaxine has a low incidence of clinically significant increases in blood pressure at doses below 200 mg daily. As with other antidepressants that may affect blood pressure, the clinician should periodically monitor blood pressure in patients treated with venlafaxine.