Bupropion Dosing in Canada
Bupropion is available in Canada in sustained-release (SR) and extended-release (XL) formulations, with specific dosing that differs by formulation and indication.
Available Formulations and Doses
Sustained-Release (SR) Formulation
- Starting dose: 100-150 mg orally once daily 1
- Maintenance dose: 100-150 mg orally twice daily (BID) 1
- Maximum dose: 300 mg per day 2
For smoking cessation specifically, the dosing schedule is 2:
- Days 1-3: 150 mg orally once daily
- Day 4 through 12 weeks: 150 mg orally twice daily (if tolerated)
- Maximum: 300 mg per day
Extended-Release (XL) Formulation
- Starting dose: 150 mg orally once daily 1
- Maintenance dose: 150-300 mg orally once daily 1
- Maximum dose: 450 mg per day 1
Key Dosing Considerations
Initiate dosing 1-2 weeks prior to quitting smoking when used for smoking cessation 2. This allows the medication to reach therapeutic levels before the quit date.
Special Populations Requiring Dose Adjustment
Renal impairment: Consider reduced dose and/or frequency in patients with glomerular filtration rate <90 mL/min, as bupropion and metabolites are cleared renally 3.
Hepatic impairment 3:
- Moderate to severe (Child-Pugh 7-15): Maximum 150 mg every other day for XL formulation
- Mild (Child-Pugh 5-6): Consider reducing dose and/or frequency
Critical Safety Information
Seizure risk is dose-dependent and represents the most serious adverse effect. The risk increases significantly above maximum recommended doses 2. Bupropion is contraindicated in patients with seizure disorders, brain metastases, or conditions that lower seizure threshold 2.
Avoid late-day dosing of the second SR dose to minimize insomnia risk 2.
Monitor for neuropsychiatric symptoms including depression, suicidal ideation, and behavioral changes, though recent large trials showed no significant increase compared to placebo 2.