Accidental Bupropion SR Overdose: 600 mg vs 450 mg Daily Dose
If you accidentally take 600 mg of bupropion SR instead of your prescribed 450 mg, you are at increased risk for seizures and should seek immediate medical evaluation, particularly if you develop agitation, tremors, or feel "jittery"—these symptoms predict higher seizure risk.
Primary Concern: Seizure Risk
The FDA explicitly states that seizure risk with bupropion is dose-related and can be minimized by limiting the daily dose to 450 mg 1. Taking 600 mg exceeds this maximum recommended dose and places you in overdose territory.
What the Evidence Shows:
- Seizure incidence: In therapeutic error cases, seizures occurred in approximately 0.8-1% of patients who accidentally took extra doses 2, 3
- Dose relationship: Patients who seized had a median reported dose of 900 mg, but seizures have been documented at doses as low as 600 mg 2
- Timing is critical: Seizures can occur 0.5 to 24 hours after ingestion, with 32% of seizures occurring after 8 hours. This delayed onset means you're not safe just because nothing happens immediately 4
- Recurrence risk: Nearly 50% of patients who seize will have subsequent seizures 4
Warning Signs to Monitor
You are at significantly higher risk if you develop these symptoms 2:
- Agitation, anxiety, or feeling "jittery" (occurred in 83% of patients who later seized)
- Tremors (present in 40.5% of seizure patients vs only 17.5% without seizures, p=0.005)
- Tachycardia or palpitations
These neurologic symptoms are harbingers of more severe toxicity and should prompt immediate emergency department evaluation 2, 4.
Immediate Actions Required
Do NOT take your next scheduled dose until you've been medically evaluated
Call Poison Control (1-800-222-1222) or your healthcare provider immediately
Go to the emergency department if you experience:
- Any of the warning signs above
- Confusion or altered mental status
- Hallucinations
- Rapid heartbeat
Minimum observation period: The evidence supports 24 hours of observation for bupropion XL overdoses ≥600 mg, as seizures can be delayed 4
Other Adverse Effects at This Dose
Beyond seizures, you may experience 2, 3:
- Agitation (8.2% of cases)
- Dizziness (7.4%)
- Tremor (7.1%)
- Nausea/vomiting (6.7%)
- Tachycardia (5.5%)
- Drowsiness (6.1%)
Clinical Context
While one study suggested home management may be an option for doses up to 900 mg in "appropriate patient populations" 2, this was in the context of poison center surveillance with specific monitoring protocols. Your 600 mg dose is 33% above the FDA maximum, and the delayed seizure risk makes this a medical urgency requiring professional evaluation 1, 4.
The fact that you're already on 450 mg daily (the maximum dose) means you have chronic bupropion exposure, which may affect your seizure threshold differently than acute-only exposures studied in the research.
Critical Pitfall to Avoid
Do not assume you're safe just because you feel fine initially. The delayed onset of seizures (up to 24 hours) with extended-release formulations is well-documented and can occur without any preceding symptoms in some patients 4.