Vivitrol and Elevated Blood Pressure
Vivitrol (extended-release injectable naltrexone) can cause elevated blood pressure, particularly when combined with bupropion in the naltrexone-bupropion ER formulation, and requires baseline assessment and periodic monitoring throughout treatment. 1
Evidence for Blood Pressure Elevation
The most direct evidence comes from the naltrexone-bupropion ER combination product used for weight management. This formulation is contraindicated in patients with uncontrolled hypertension, and elevated heart rate and blood pressure are listed as common safety concerns. 1 The bupropion component is the primary driver of blood pressure increases, as bupropion can elevate both blood pressure and heart rate through its noradrenergic effects. 2
Blood pressure and heart rate must be monitored periodically during treatment, especially during the first 12 weeks, as this is when cardiovascular effects are most likely to manifest. 2, 3 The 2017 ACC/AHA hypertension guidelines classify naltrexone-bupropion among agents that may impair blood pressure control and recommend avoiding use in patients with severe or uncontrolled hypertension. 1
Monitoring Protocol
Before initiating Vivitrol (especially naltrexone-bupropion combinations):
- Measure baseline blood pressure and heart rate 2, 3
- Screen for uncontrolled hypertension (defined as BP ≥140/90 mm Hg or ≥130/80 mm Hg in high-risk patients) 1
- Assess for other cardiovascular risk factors 2
During treatment:
- Monitor blood pressure and heart rate at weeks 2,4,8, and 12, then periodically thereafter 2, 3
- If blood pressure rises above goal (≥130/80 mm Hg for most patients), consider dose reduction, addition of antihypertensive therapy, or discontinuation 1
- For the naltrexone-bupropion ER combination, the maximum bupropion dose should not exceed 360 mg/day to minimize cardiovascular risk 1
Mechanism and Clinical Context
The blood pressure elevation is primarily attributable to bupropion's effects on norepinephrine and dopamine reuptake inhibition, which increases sympathetic tone. 2 Naltrexone monotherapy (without bupropion) has minimal direct cardiovascular effects, though the phase III trial of extended-release naltrexone 380 mg monthly reported hypertension as one of the more common adverse events (incidence ≥5%) that occurred more frequently than placebo. 4
Management of Elevated Blood Pressure
If blood pressure becomes elevated during Vivitrol treatment:
- For naltrexone-bupropion ER: reduce the dose or discontinue if blood pressure cannot be controlled with antihypertensive therapy 1, 2
- For naltrexone monotherapy: hypertension is less common but should still prompt standard antihypertensive management 4
- Consider alternative medications for opioid or alcohol dependence if blood pressure remains uncontrolled 1
Special Populations
Patients with hepatic or renal impairment require dose adjustments that may also affect cardiovascular risk. For moderate to severe hepatic impairment, the maximum bupropion dose is 150 mg daily; for moderate to severe renal impairment, reduce the total daily dose by 50%. 2 These adjustments may help minimize blood pressure effects while maintaining therapeutic benefit.
Common Pitfalls
- Failing to measure baseline blood pressure before initiating treatment is a critical error, as it prevents identification of pre-existing uncontrolled hypertension 2, 3
- Assuming naltrexone monotherapy has no cardiovascular effects—while less common than with naltrexone-bupropion, hypertension was reported in the pivotal trial 4
- Not monitoring blood pressure during the first 12 weeks, when cardiovascular effects are most likely to emerge 2, 3