From the Guidelines
When switching from Effexor XR (venlafaxine) to Wellbutrin (bupropion), a cross-taper approach is recommended to minimize withdrawal symptoms and side effects. This approach is based on the principle of gradually reducing the dose of Effexor XR while simultaneously introducing Wellbutrin at a low dose, as moderate-quality evidence from trials such as 1 suggests no significant difference in response when switching from one serotonin-norepinephrine reuptake inhibitor (SNRI) or selective serotonin reuptake inhibitor (SSRI) to another, including bupropion.
Key Considerations for the Cross-Taper:
- Begin by reducing Effexor XR by 37.5-75 mg every 5-7 days.
- Start Wellbutrin XL at 150 mg daily for the first week, then increase to 300 mg daily if tolerated.
- The cross-taper typically takes 2-4 weeks, depending on the initial Effexor XR dose.
- Monitor for withdrawal effects from Effexor XR, such as dizziness, nausea, headache, and irritability, and side effects from Wellbutrin, including insomnia, headache, dry mouth, and agitation.
- Wellbutrin should be taken in the morning to minimize sleep disturbances.
- Be aware that the seizure risk increases at higher doses of Wellbutrin, so do not exceed recommended dosages.
Rationale for the Switch:
The decision to switch from Effexor XR to Wellbutrin may be based on the patient's response to treatment, side effect profile, or specific symptoms that one medication may address better than the other, as suggested by low-quality evidence from trials such as 1.
Important Notes:
- This transition should always be conducted under medical supervision to adjust the doses appropriately and manage any adverse effects.
- The mechanism of action differs between Effexor XR (affecting serotonin and norepinephrine) and Wellbutrin (primarily affecting dopamine and norepinephrine), which may explain why some patients respond better to one medication than the other, as indicated by moderate-quality evidence from studies like 1.
From the Research
Switching from Effexor XR to Wellbutrin
To switch from Effexor XR (venlafaxine) to Wellbutrin (bupropion), consider the following steps:
- Gradually taper off Effexor XR to minimize withdrawal symptoms, as recommended by clinical practice guidelines 2
- Initiate Wellbutrin at a low dose and gradually increase as needed and tolerated
- Monitor patient response and adjust dosage accordingly
Considerations
- The efficacy of venlafaxine and bupropion in treating depression has been compared in several studies, with mixed results 3, 4, 5
- Bupropion may have a lower risk of switch in mood polarity to hypomania or mania compared to venlafaxine in patients with bipolar depression 6
- Short-term treatments of venlafaxine and bupropion were found to be equally effective in a study of patients with bipolar II disorder 5