Switching from Bupropion 75mg IR to Higher Dose ER
When switching from bupropion 75mg IR to a higher dose ER formulation, give the same total daily dose when possible, starting with 150mg XL once daily in the morning, then increase to 300mg XL once daily after 4 days if tolerated. 1
Direct Switching Strategy
The FDA label explicitly states that when switching between bupropion formulations, you should give the same total daily dose when possible. 1
Since the patient is currently on 75mg IR (likely once or twice daily for a total of 75-150mg/day), start with bupropion XL 150mg once daily in the morning. 1
After 4 days at 150mg XL, increase to the target dose of 300mg XL once daily in the morning if the patient tolerates the initial dose and requires higher dosing for therapeutic effect. 1
Gradual Titration Approach for Safety
To minimize seizure risk, the dose must be increased gradually regardless of formulation. 1
The XL formulation should be swallowed whole (not crushed, divided, or chewed) and administered in the morning with or without food. 1
For patients requiring more cautious titration (older adults, multiple medications, or seizure risk factors), start with 150mg XL once daily and wait at least 4-7 days before increasing to 300mg XL. 2, 1
Maximum Dosing and Safety Limits
The maximum dose for bupropion XL is 450mg per day, though most patients achieve therapeutic benefit at 300mg daily. 2
Do not exceed 300mg as a single dose to minimize seizure risk, which occurs at approximately 0.1% at recommended doses. 3
Doses above 450mg/day significantly increase seizure risk and should never be used. 2, 4
Special Population Adjustments
For moderate to severe hepatic impairment (Child-Pugh 7-15), the maximum dose is 150mg every other day. 1
For mild hepatic impairment (Child-Pugh 5-6), consider reducing dose and/or frequency. 1
For renal impairment (GFR <90 mL/min), reduce the dose and/or frequency of administration. 1
For older adults, start with lower doses (approximately 50% of standard) and titrate more slowly every 3 days to minimize adverse reactions. 2
Monitoring During Transition
Monitor for activating side effects including insomnia, agitation, anxiety, and headache, which are the most common adverse events. 3, 5
Administer the dose in the morning to leverage activating properties and minimize insomnia risk. 2
Watch for signs of seizure risk factors: history of seizures, eating disorders (bulimia/anorexia), abrupt alcohol or benzodiazepine withdrawal, or concurrent medications that lower seizure threshold. 1, 4
Monitor blood pressure, as bupropion can cause modest increases, particularly in the first 8 weeks. 6
Common Pitfalls to Avoid
Never crush, divide, or chew XL tablets, as this destroys the extended-release mechanism and increases seizure risk. 1
Do not increase the dose more frequently than every 4 days, as this increases adverse event risk without improving efficacy. 1
Avoid late-day dosing of any bupropion formulation, as insomnia is the most common reason for discontinuation. 2, 3
Screen carefully for seizure risk factors before initiating or increasing doses, as bupropion lowers the seizure threshold. 1, 4
Efficacy Assessment Timeline
Assess therapeutic response after 6-8 weeks at an adequate dose (typically 300mg XL daily). 2
If no response after this period, consider alternative treatments rather than further dose escalation beyond 300mg. 2
Acute depressive episodes require several months or longer of treatment beyond initial response. 1