What is the effect of venlafaxine (Effexor) on blood pressure?

From the Guidelines

Venlafaxine can increase blood pressure, typically by 1-3 mmHg on average, though the effect is dose-dependent with higher doses (225 mg/day or more) causing more significant elevations. At lower doses (75 mg/day), blood pressure changes are minimal, but at doses of 300-375 mg/day, approximately 13% of patients experience a sustained increase of 10 mmHg or more in diastolic blood pressure. This effect occurs because venlafaxine inhibits the reuptake of norepinephrine, which can cause vasoconstriction and increased peripheral resistance 1. Blood pressure changes typically begin within the first few weeks of treatment and may persist while on the medication. Patients taking venlafaxine should have their blood pressure monitored regularly, especially when starting treatment or increasing doses. Those with pre-existing hypertension or cardiovascular disease should be monitored more closely. If significant blood pressure increases occur, dose reduction or switching to an alternative antidepressant with less impact on blood pressure might be necessary. Some key points to consider when managing blood pressure in patients taking venlafaxine include:

• Monitoring blood pressure regularly, especially in patients with pre-existing hypertension or cardiovascular disease
• Being aware of the potential for dose-dependent increases in blood pressure
• Considering alternative antidepressants with less impact on blood pressure if significant increases occur
• Weighing the benefits and risks of treatment, including the potential for increased blood pressure, against the benefits of symptom relief and improved quality of life 1.

From the FDA Drug Label

Venlafaxine treatment is associated with sustained increases in blood pressure in some patients An analysis for patients meeting criteria for sustained hypertension (defined as treatment-emergent SDBP ≥ 90 mm Hg and ≥ 10 mm Hg above baseline for 3 consecutive visits) revealed a dose-dependent increase in the incidence of sustained hypertension for venlafaxine: Probability of Sustained Elevation in SDBP (Pool of Premarketing Venlafaxine Studies) Treatment GroupIncidence of SustainedElevation in SDBP Venlafaxine < 100 mg/day3% 101 to 200 mg/day5% 201 to 300 mg/day7%

300 mg/day13% Placebo2% An analysis of the patients with sustained hypertension and the 19 venlafaxine patients who were discontinued from treatment because of hypertension (<1% of total venlafaxine-treated group) revealed that most of the blood pressure increases were in a modest range (10 to 15 mm Hg, SDBP)

Venlafaxine increases blood pressure in a dose-dependent manner. The mean increase in supine diastolic blood pressure (SDBP) was 7.2 mm Hg in the 375 mg/day group. Most blood pressure increases were in a modest range of 10 to 15 mm Hg.

• The incidence of sustained hypertension was:

• 3% for venlafaxine < 100 mg/day
• 5% for 101 to 200 mg/day
• 7% for 201 to 300 mg/day
• 13% for > 300 mg/day
• 2% for placebo It is recommended that patients receiving venlafaxine have regular monitoring of blood pressure 2

From the Research

Effects of Venlafaxine on Blood Pressure

• Venlafaxine can cause both transient and sustained elevations of supine diastolic blood pressure (SDBP), probably due to noradrenergic potentiation 3.
• The effect of venlafaxine on SDBP is highly dose-dependent, and the incidence of elevated SDBP is statistically and clinically significant only at dosages above 300 mg/day 3, 4.
• 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 4.
• The mean increase in diastolic blood pressure was 7 mm Hg after 6 weeks of treatment with doses of 300 to 375 mg daily 4.
• Venlafaxine did not adversely affect the control of blood pressure for patients with preexisting high blood pressure or elevated baseline values 3.

Comparison with Other Antidepressants

• The overall incidence of clinically significant blood pressure increases with venlafaxine was similar to that of tricyclic antidepressants 4.
• Selective serotonin reuptake inhibitors are characterized by limited effects on autonomic system activity and a lower impact on blood pressure, making them a safer option, particularly among elderly and cardiovascular patients 5.
• Serotonin-norepinephrine reuptake inhibitors, particularly venlafaxine, carry a greater risk of hypertension, possibly related to greater effects on the sympathetic nervous system 5.

Special Considerations

• Older adults treated with venlafaxine are at risk for orthostatic hypotension, which can increase the risk of falls 6.
• A large proportion of older adults treated with venlafaxine experience orthostatic hypotension, while a smaller proportion experience elevated BP 6.
• Clinicians should carefully consider the blood pressure status and cardiovascular comorbidities of patients when prescribing venlafaxine, and monitor blood pressure regularly 4, 5.