Management of Resting Tremors in a Patient on Bupropion
Tremor is a recognized adverse effect of bupropion that warrants dose reduction or discontinuation, particularly when it occurs as a resting tremor, as this is among the most common adverse effects leading to drug discontinuation in clinical trials. 1
Immediate Assessment
Evaluate whether this is truly a resting tremor versus an action tremor, as this distinction is critical:
- Resting tremor: Present when limbs are at rest, may suggest drug-induced parkinsonism
- Action tremor: More common with bupropion, occurs with voluntary movement
- Check for other parkinsonian features: bradykinesia, rigidity, postural instability
The FDA drug label explicitly identifies tremor as one of the most common adverse effects associated with bupropion discontinuation in clinical trials, with dropout rates of 7-12% attributed to tremor, rash, headache, and urticaria 2.
Management Algorithm
Step 1: Assess Severity and Dose
- Current bupropion dose: If patient is on 300 mg/day, this is dose-related 1
- Duration of therapy: Tremor typically emerges after dose escalation 3
- Functional impairment: Determine if tremor interferes with daily activities
Step 2: Immediate Action Based on Severity
For mild tremor without functional impairment:
- Reduce bupropion dose by 50% (e.g., from 300 mg to 150 mg daily) 2
- Monitor for improvement over 36-48 hours 3
- If tremor persists at lower dose, discontinue medication
For moderate-to-severe tremor or any resting tremor:
- Discontinue bupropion immediately 1
- Tremor should resolve within 24-48 hours of discontinuation 3, 4
- Consider short-term benzodiazepine (e.g., clonazepam) if tremor is distressing, though most cases resolve with drug withdrawal alone 4
Step 3: Rule Out Bupropion Toxicity
Check for additional concerning features that suggest toxicity rather than simple adverse effect 3, 5:
- Altered mental status, confusion, or delirium
- Visual or auditory hallucinations
- Myoclonic jerks
- Truncal ataxia
- Seizure activity
If any of these are present, this represents bupropion toxicity requiring immediate discontinuation and supportive care.
Critical Pitfalls to Avoid
Do not misdiagnose as Parkinson's disease. Bupropion can cause both tremor and decreased dopamine transporter binding on imaging studies (SPECT), potentially leading to false-positive PD diagnosis 6. If PD is suspected:
- Discontinue bupropion for 14 days before any imaging studies
- Do not initiate anti-Parkinsonian medications without confirming diagnosis off bupropion
- Repeat imaging after 14-day washout if initially abnormal 6
Do not continue bupropion hoping tremor will resolve. Unlike some antidepressant side effects that diminish over time, tremor is a dose-related adverse effect that typically requires intervention 1.
Special Populations Requiring Extra Caution
Elderly patients and those with renal impairment (GFR < 90 mL/min) have reduced bupropion clearance and are at higher risk for tremor and other neurologic adverse effects 2, 3. In these patients:
- Consider dose reduction as first-line even for mild tremor
- Maximum dose should not exceed 150 mg daily in moderate-to-severe renal impairment 2
Alternative Antidepressant Selection
After bupropion discontinuation, consider switching to: