From the Research
Bupropion XL is generally preferred over bupropion SR due to its more convenient once-daily dosing and potentially better adherence, as well as its more gradual and consistent release of medication over 24 hours, which may result in fewer peak-related side effects. The primary difference between bupropion SR and bupropion XL lies in their release mechanisms and dosing schedules. Bupropion SR is taken twice daily, typically at doses of 150 mg twice a day, with at least 8 hours between doses to maintain therapeutic levels throughout the day 1. In contrast, bupropion XL is taken once daily, usually in the morning, at doses of 150-450 mg, offering more convenient dosing and potentially better adherence 2. Both formulations contain the same active ingredient and work by inhibiting the reuptake of dopamine and norepinephrine, but the XL formulation may be preferred for patients who have difficulty remembering multiple daily doses or who experience more side effects with the SR formulation's more variable blood levels 3. When switching between formulations, the total daily dose typically remains the same, though individual responses may vary. Key points to consider when choosing between bupropion SR and XL include:
- Patient preference for dosing schedule
- Side effect profile, with the XL formulation potentially offering fewer peak-related side effects
- Insurance coverage, which may vary between the two formulations
- Efficacy for treating depression and as a smoking cessation aid, with both formulations being effective but potentially differing in individual patient response 4, 5.