How does bupropion affect blood pressure and what dosing and monitoring are recommended?

Bupropion and Blood Pressure: Effects, Dosing, and Monitoring

Bupropion can increase blood pressure and should be avoided in patients with uncontrolled hypertension, while requiring periodic blood pressure and heart rate monitoring in all patients, especially during the first 12 weeks of treatment. 1

Blood Pressure Effects

Bupropion causes modest but clinically significant increases in blood pressure through its dopamine and norepinephrine reuptake inhibition. The FDA drug label explicitly warns that bupropion can result in elevated blood pressure and hypertension, requiring blood pressure assessment before initiating treatment and periodic monitoring during therapy. 2

Magnitude of Blood Pressure Changes

The blood pressure effects vary by formulation and clinical context:

• In obesity trials with naltrexone-bupropion ER: Studies showed modest but statistically significant increases in systolic and diastolic blood pressure, most prominently in the first 8 weeks, though differences were not significant by 12 weeks 1
• In seasonal affective disorder trials: Mean systolic blood pressure increased by 1.3 mmHg (statistically significant, p=0.013), while diastolic increased by 0.8 mmHg (not statistically significant) 2
• In ADHD treatment: Bupropion increased systolic blood pressure by 5.9 mmHg (p<0.05) and heart rate by 6.9 beats per minute (p<0.05) 3
• In mild hypertension study: A controlled trial in patients with untreated stage 1 hypertension showed that while all groups (including placebo) had blood pressure reductions, the decrease in systolic blood pressure was less with bupropion SR 300 mg/day compared to placebo (-4.20 vs -6.53 mmHg; p=0.020) 4

Importantly, in depressed patients with preexisting heart disease, bupropion caused a rise in supine blood pressure and led to treatment discontinuation in 14% of patients, including two cases of exacerbated baseline hypertension. 5

Contraindications and Precautions

Naltrexone-bupropion ER is contraindicated in patients with uncontrolled hypertension and should be avoided as a first-line weight loss medication in patients with existing hypertension, as weight loss assisted by this combination cannot be expected to reduce blood pressure. 1, 6

The 2016 AACE/ACE guidelines explicitly state: "Naltrexone ER/bupropion ER should be avoided if other weight-loss medications can be used because weight loss assisted by naltrexone ER/bupropion ER cannot be expected to reduce blood pressure, and the drug is contraindicated in uncontrolled hypertension." 6

Preferred Alternatives in Hypertensive Patients

For patients with existing hypertension requiring weight loss medication, preferred options include orlistat, lorcaserin, phentermine/topiramate ER, and liraglutide 3 mg 6. These medications have more favorable blood pressure profiles.

Dosing Recommendations

Naltrexone-Bupropion ER for Weight Management

Standard titration schedule 1:

• Week 1: 1 tablet (8 mg naltrexone/90 mg bupropion) daily in the morning
• Week 2: 1 tablet twice daily
• Week 3: 2 tablets in the morning, 1 tablet in the afternoon
• Week 4 onward: Maintenance dose of 2 tablets twice daily (total daily dose: 32 mg naltrexone/360 mg bupropion)

Critical timing consideration: The second dose should not be taken late in the day to minimize insomnia risk 1

Dose Adjustments for Organ Impairment

Renal impairment 1, 6:

• Moderate to severe (CrCl 30-49 mL/min): Reduce total daily dose by half (1 tablet twice daily; maximum 8 mg/90 mg twice daily)
• Severe (<30 mL/min): Not recommended
• End-stage renal disease: Avoid completely

Hepatic impairment 1, 6:

• Moderate impairment: Maximum dose of 1 tablet (8 mg/90 mg) daily in the morning
• Severe impairment (Child-Pugh score >9): Avoid

Monitoring Protocol

Blood pressure and heart rate must be monitored periodically while taking naltrexone-bupropion ER, with particular attention during the first 12 weeks of treatment. 1

Specific Monitoring Recommendations

1. Baseline assessment: Measure blood pressure before initiating treatment 2
2. Early treatment phase: Monitor closely during the first 12 weeks, when blood pressure increases are most prominent 1
3. Ongoing monitoring: Continue periodic blood pressure and heart rate checks throughout treatment 1
4. Combination therapy: When bupropion is combined with nicotine replacement therapy (NRT), monitoring is especially important as the combination increases hypertension risk (6.1% vs 2.5% with bupropion alone) 2

Treatment Response Assessment

After 12 weeks of therapy on the maintenance dose, discontinue the medication if the patient has not lost 5% of their total body weight, as they are likely a poor responder. 1

Common Pitfalls and Clinical Considerations

Cardiovascular Safety Concerns

The long-term cardiovascular safety of naltrexone-bupropion ER remains unclear. An FDA-mandated cardiovascular outcome trial was terminated early due to publication of confidential results at the 25% interim analysis, and a subsequent trial was terminated prematurely due to poor recruitment 1. This uncertainty should factor into prescribing decisions for patients with cardiovascular risk factors.

Risk of Hypertensive Crisis

The risk of hypertension is significantly increased when bupropion is used concomitantly with MAOIs or other drugs that increase dopaminergic or noradrenergic activity 2. Bupropion is contraindicated within 14 days of MAOI use. 1

Special Populations

Patients with preexisting cardiovascular disease: While bupropion may be used cautiously in patients with stable heart disease, two patients in one study developed exacerbation of baseline hypertension requiring discontinuation 5. Orlistat and lorcaserin are preferred weight-loss medications in this population 6.

Elderly patients: Given the increased cardiovascular risk and potential for orthostatic changes, careful blood pressure monitoring is essential, though bupropion has a wider safety margin compared to tricyclic antidepressants 7.