A 47-year-old woman ingested an overdose of 8000 mg quetiapine. The treatment had been initiated 3 weeks before. The current medications were lamuvidine, ritonavir, atazanavir and tenofovir for an HIV infection. The patient presented a deep coma and sustained hypotension as main complications. The toxicokinetic data revealed a markedly prolonged elimination half-life for quetiapine (62.4 hours) and the relationship with antiretroviral therapy is discussed.