How should I manage a patient's current bupropion (Wellbutrin) 150mg regimen when initiating Contrave (bupropion and naltrexone)?

Managing Bupropion When Starting Contrave

You must discontinue the standalone bupropion 150mg before initiating Contrave, as Contrave already contains bupropion and continuing both would result in dangerous bupropion overdosing that significantly increases seizure risk. 1

Why This Matters

Contrave is a fixed-dose combination containing naltrexone 8mg and bupropion 90mg per tablet, with the full maintenance dose being two tablets twice daily (total daily bupropion: 360mg) 2, 3. Your patient is currently taking bupropion 150mg daily. If you add Contrave without stopping the standalone bupropion, the patient would receive:

• 510mg total daily bupropion (150mg from standalone + 360mg from Contrave at full dose)
• This exceeds the maximum safe dose of 450mg/day and dramatically increases seizure risk 4, 1

Step-by-Step Protocol

1. Discontinue Standalone Bupropion First

• Stop the bupropion 150mg completely 1
• No tapering is required when discontinuing bupropion 150mg once daily, as this is already a low dose 1
• Wait at least 24 hours after the last dose of standalone bupropion before starting Contrave 1

2. Initiate Contrave Using Standard Titration

• Week 1: One tablet (8mg naltrexone/90mg bupropion) every morning 2
• Week 2: One tablet twice daily (morning and evening) 2
• Week 3: Two tablets in morning, one tablet in evening 2
• Week 4 onward: Two tablets twice daily (maintenance dose = 360mg bupropion daily) 2

3. Monitor Closely During Transition

• Watch for depression recurrence during the first 1-2 weeks, as there will be a brief period of lower total bupropion exposure 4
• Monitor blood pressure and heart rate at each visit, as both bupropion and naltrexone can elevate these parameters 2, 5
• Screen for neuropsychiatric symptoms including mood changes, anxiety, suicidal ideation, especially in patients under 24 years old 2, 4

Critical Safety Considerations

Seizure Risk Management

• The maximum safe bupropion dose is 450mg/day; exceeding this substantially increases seizure risk 4, 1
• Never combine Contrave with any other bupropion-containing product 1
• Avoid in patients with seizure disorders, eating disorders (bulimia/anorexia), or abrupt discontinuation of alcohol/benzodiazepines 2, 4

Efficacy Assessment Timeline

• Assess weight loss at 12 weeks on the maintenance dose 2
• Discontinue Contrave if the patient has not lost at least 5% of baseline body weight by 12 weeks, as continued use is unlikely to provide meaningful benefit 2

Special Population Adjustments

• Hepatic impairment (moderate to severe): Maximum dose is one tablet daily (not applicable for Contrave's fixed combination) 4
• Renal impairment (GFR <90): Reduce dose by half and monitor closely 4
• Uncontrolled hypertension: Contrave is contraindicated 2, 5

Common Pitfall to Avoid

Do not attempt to "bridge" the patient by overlapping medications or using partial doses of both. The bupropion content in Contrave cannot be separated from the naltrexone, and any overlap creates unacceptable seizure risk. Make a clean switch: stop standalone bupropion completely, then start Contrave fresh 1.