AstraZeneca Pharmaceuticals has received reports of medication errors involving confusion between its atypical antipsychotic Seroquel (quetiapine fumarate), indicated for the treatment of schizophrenia, and Serzone (nefazodone hydrochloride), a product of Bristol-Myers Squibb, indicated for the treatment of depression. In addition to the similarity in names between Seroquel and Serzone, the overlapping strengths (100 mg and 200 mg), the dosage forms (tablets), the dosing interval (BID), and the fact that these two products were stocked close together in pharmacies were also critical in causing these errors.

According to the reports, prescriptions for the two drugs were misinterpreted. Adverse events included hallucinations, delusions, nausea, diarrhea, muscle weakness and lethargy. Although it has not been determined if the prescription error was the exact cause, a 25-year-old woman died after taking Seroquel instead of Serzone.