Effects of Venlafaxine on Blood Pressure: A Meta-Analysis of Original Data From 3744 Depressed Patients

Background: Venlafaxine hydrochloride, a structurally novelantidepressant, is also the first nontricyclic serotonin/norepinephrine reuptakeinhibitor. Although venlafaxine has an overall side effect and safety profile that iscomparable to other newer antidepressants, it can cause both transient and sustainedelevations of supine diastolic blood pressure (SDBP), probably the result of noradrenergicpotentiation.

Method: Presented here is a meta-analysis of original data on bloodpressure, using both random effects and a multivariate survival analyses. The sampleconsisted of 3744 patients with major depression who were studied in controlled clinicaltrials comparing venlafaxine with imipramine and/or placebo. Patients were treated for 6weeks of acute phase therapy; some responders received up to 1 year of continuationphase therapy.

Results: Venlafaxine and imipramine were associated with small, butstatistically significant, increases in SDBP during acute phase therapy. When comparedwith imipramine and placebo, venlafaxine was also associated with a greater proportion ofpersistent elevations of SDBP during continuation therapy. The effect of venlafaxine washighly dose dependent, and the incidence of elevated SDBP was statistically and clinicallysignificant only at dosages above 300 mg/day. Venlafaxine did not adversely affect thecontrol of blood pressure for patients with preexisting high blood pressure or elevatedbaseline values.

Conclusion: Venlafaxine has a dose-dependent effect on SDBP that isclinically significant at high dosages. Concern about blood pressure effects should notdeter first-line use of this effective antidepressant, although more extensive studies ofpatients with cardiovascular diseases are still necessary.