April Tox: Wellbutrin

Brief Clinical Course

67F PMH Bipolar disorder, suicide attempt, admitted overdosing on Risperdal 1 mg x 90, Risperdal 3 mg x 90, Atorvastatin 10 mg x 90, Wellbutrin XL 150 mg x 90, Wellbutrin XL 300 mg x 90. 

4/15, Patient initially admitted to Piedmont Henry. 4/16 seizure x1, intubated at that time, transferred to ICU requiring 3 pressors (NE, vasopressin, and Epi). QTc 600 but improved w/ Mg and K repletement.  

4/17 Due to refractory shock and potential need for ECMO, patient was transferred to Kennestone. She was intermittently placed back on levophed low dose (2-3 mcg/min) but eventually weaned off all pressors by 4/21 and did not require ECMO. She was eventually extubated, QTc normalized, QRS remained stable, and encephalopathy resolved.  


Wellbutrin Quick Take Home Points

Buproprion (Wellbutrin) is an atypical anti-depressant, chemically un-related to other antidepressants and as an aminoketone class, most closely resembles the structure of amphetamine so think of an overdose like an amphetamine with lots of seizures. It functions as a dopamine > NE reuptake inhibitor. Clinical symptoms to watch out for include: Seizures, delirium, tachycardia, HTN, serotonin syndorme,  hypotension, QRS prolongation, QT prolongation, and cardiac arrest.  

Buproprion induced seizures are responsive to standard benzo / phenobarb therapy. 

What makes Buproprion particularly difficult to manage are the cardiogenic effects it causes via inhibition of gap junctions (prolongs QRS) and blockade of cardiac potassium channels (prolongs QTc). In this situation Sodium Bicarbonate has no effect on QRS prolongation. Intralipid emulsion therapy has been recommended if the patient is with life-threatening cardiac toxicity. ECMO is definitive therapy if the patient develops refractory cardiogenic shock. Overdose >10 grams has been associated with cardiac toxicity. Our patient took 40.5 grams. 

Buproprion XL peak plasma concentration 5 hours. Half life 20-37 hours. Any patient with an ingestion of buproprion XL or SR formulation should be admitted for 24hr obs as literature has shown the first seizure can occur up to 21 hrs post overdose. This is one of the few exceptions to the idea that most asymptomatic patients can be observed 4-6hrs and cleared. 

Take home points: Wellbutrin induced cardiogenic shock is no joke. Monitor QRS/QTC, optimize electrolytes (Mg and K), if crashing use pressors, if widening QRS try NaHCO3, if it doesn’t work, give intralipid. If the patient is decompensating despite multiple pressors, send to ECMO capable facility. Admit even asymptomatic pts with extended release formulations. 




Goldfrank’s Toxicologic Emergencies – 11th Edition 

Poisoning and Drug overdose – California Poison Control System 

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