Wellbutrin XL is Recommended Over XR for Most Patients
For most patients requiring bupropion (Wellbutrin) therapy, the XL (extended release) formulation is recommended over the XR formulation due to its once-daily dosing convenience and established efficacy profile. 1
Formulation Differences and Benefits
Wellbutrin is available in three formulations with different dosing schedules:
All three formulations are bioequivalent in terms of systemic exposure to bupropion, but differ in their release mechanisms and dosing frequency 2, 4
The XL formulation offers significant advantages:
Dosing Considerations
For major depressive disorder, Wellbutrin XL is typically administered as 300 mg once daily in the morning 1
Initial dosing may start at 150 mg once daily and can be increased to 300 mg once daily after several days if well tolerated 1
Maximum recommended dose for Wellbutrin XL is 450 mg per day to minimize seizure risk 1
For patients with moderate to severe hepatic impairment, the total daily dose should not exceed 150 mg 1
For moderate to severe renal impairment, the total daily dose should be reduced by half 1
Special Considerations and Monitoring
Bupropion may lower the seizure threshold and should be avoided in patients with seizure disorders 1
Avoid use with monoamine oxidase inhibitors (MAOIs) or within 14 days of discontinuing MAOIs 1
Monitor vital signs, particularly blood pressure, as bupropion should be avoided in patients with uncontrolled hypertension 1
Patients should be observed for neuropsychiatric adverse effects, including suicidal thoughts and behaviors, especially in individuals younger than 24 years 5
To minimize risk of insomnia, administer the medication in the morning 1
Clinical Pearls
Bupropion may be particularly beneficial for patients with depression who also want to quit smoking 1
Unlike many other antidepressants, bupropion has a lower incidence of sexual dysfunction and weight gain 2, 3
If no response is seen after 6-8 weeks at an adequate dose, consider alternative treatment 1
For older adults, consider starting with a lower dose (approximately 50% of standard dose) due to increased risk of adverse reactions 1
Important Note on Formulation Terminology
It's important to clarify that in the US market, the extended-release formulation is marketed as "Wellbutrin XL" (not XR). The terms "XR" and "XL" sometimes appear interchangeably in literature, but Wellbutrin XL is the FDA-approved once-daily formulation available in the United States 1, 2, 3.