Multiple complications and withdrawal syndrome associated with quetiapine/venlafaxine intoxication.
OBJECTIVE
To report a case of quetiapine/venlafaxine intoxication associated with multiple complications and to review their possible relationship with these 2 drugs.


METHODS
A 53-year-old white man was admitted to the hospital for loss of consciousness secondary to voluntary intoxication with venlafaxine and quetiapine. Several complications were attributable to this intoxication including seizures, prolonged coma, respiratory depression, neuroleptic malignant syndrome, prolonged QRS and QTc intervals, and a possible venlafaxine withdrawal syndrome.


CONCLUSIONS
Quetiapine could be responsible for the neuroleptic malignant syndrome presented in this case. Moreover, venlafaxine intoxication, fever, autonomic instability, and myoclonus presented serotonin syndrome as a differential diagnosis. Potential causes of seizures and prolongation of the QRS and QTc intervals are reviewed. Finally, prolonged coma and late venlafaxine withdrawal are discussed with regard to the pharmacodynamics and pharmacokinetics of drug elimination in the context of intoxication.


CONCLUSIONS
Clinicians should be aware of possible complications following intoxication with atypical antipsychotics and anti-depressants, including protracted altered mental status.
Précourt
Andréanne
A
Department of Pharmacy Services, Hôpital Ste-Justine, Montréal, Québec, Canada.
Dunewicz
Magdalena
M
Grégoire
Geneviève
G
Williamson
David R
DR
D003128:Coma / Q000139:chemically induced; D003511:Cyclohexanols / Q000506:poisoning*; D003937:Diagnosis, Differential; D003987:Dibenzothiazepines / Q000506:poisoning*; D062787:Drug Overdose; D004562:Electrocardiography / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D009459:Neuroleptic Malignant Syndrome / Q000175:diagnosis; D000069348:Quetiapine Fumarate; D012131:Respiratory Insufficiency / Q000139:chemically induced; D012640:Seizures / Q000139:chemically induced; D018490:Serotonin Agents / Q000506:poisoning*; D020230:Serotonin Syndrome / Q000175:diagnosis; D013375:Substance Withdrawal Syndrome / Q000175:diagnosis*; D000069470:Venlafaxine Hydrochloride
D003511:Cyclohexanols; D003987:Dibenzothiazepines; D018490:Serotonin Agents; D000069348:Quetiapine Fumarate; D000069470:Venlafaxine Hydrochloride