Starting Wellbutrin as Adjunct to Zoloft: Dosing and Timing
Yes, you can start the first dose of Wellbutrin at noon today, but the optimal approach is to begin with 150 mg once daily in the morning, then increase to 150 mg twice daily after 3 days if tolerated. 1
Initial Dosing Strategy
Start with 150 mg SR once daily for the first 3 days, then increase to 150 mg twice daily (300 mg total daily dose) if tolerated. 1 This gradual titration minimizes seizure risk while achieving therapeutic levels. 1
For patients on multiple psychotropic medications (like your patient already on Zoloft), an even more conservative approach may be warranted:
- Consider starting with 37.5 mg every morning, increasing by 37.5 mg every 3 days as tolerated, with a target dose of 150 mg twice daily (maximum 300 mg/day). 1
- This lower starting dose allows better assessment of tolerability in patients on multiple medications. 1
Timing Considerations for Today's First Dose
Since it's noon, you can start the first dose now, but ideally future doses should be taken in the morning. 1 Here's why:
- Bupropion has activating properties that can improve energy levels and reduce apathy, making morning administration ideal. 1
- The second daily dose (once titrated to twice daily) must be given before 3 PM to minimize insomnia risk. 1
- Late-day dosing significantly increases the risk of sleep disturbances. 1
Target Maintenance Dosing
The standard maintenance dose for depression is 150 mg twice daily (300 mg total daily dose) of the SR formulation. 1 This dosing:
- Provides steady drug levels throughout the day 1
- Has been shown to be more effective than placebo in treating depression 2
- Addresses depression through complementary mechanisms with sertraline (Zoloft affects serotonin; bupropion works via noradrenergic/dopaminergic pathways) 1
Critical Safety Monitoring
The maximum dose should not exceed 450 mg per day to minimize seizure risk. 1 Key safety considerations:
- Seizure risk is the most serious adverse effect, occurring at less than 1 per 1,000 at usual outpatient doses. 3
- Bupropion is contraindicated in patients with seizure disorders, as it lowers the seizure threshold. 1
- Monitor for increased agitation, as bupropion is an activating medication. 1
- Watch for neuropsychiatric adverse effects, especially in patients younger than 24 years. 1
- Monitor blood pressure, as bupropion should be avoided in patients with uncontrolled hypertension. 1
Expected Timeline for Response
- Onset of action is typically 2 weeks, with full efficacy attained at 4 weeks of treatment. 4
- Some patients may show improvement within the first 1-2 weeks. 4
- If no response is seen after 6-8 weeks at an adequate dose, consider alternative treatment. 1
Common Pitfalls to Avoid
Do not exceed 450 mg/day total dose, as doses above this threshold are associated with increased seizure risk and may precipitate mania in susceptible patients. 5 One case report documented a manic episode when bupropion was titrated to 600 mg/day in a bipolar patient, suggesting a dose-related threshold for this adverse reaction. 5
Avoid combining with MAOIs or within 14 days of discontinuing MAOIs. 1