title: Quetiapine Carboxylic Acid and Quetiapine Sulfoxide Prevalence in Patient Urine.
abstract: Treatment adherence is often an issue with mental health patients. For those prescribed quetiapine (Seroquel®), the low levels of parent drug and plasma metabolite(s) (e.g., 7-hydroxyquetiapine) typically used in urine drug monitoring can result in false negatives with concomitant unfavorable impacts on patient care. Literature review coupled with liquid chromatography/time-of-flight mass spectrometry analysis of patient positive urine samples indicated the presence of quetiapine carboxylic acid and quetiapine sulfoxide as significant urinary metabolites of quetiapine. Analysis of these two metabolites determined that they are abundant in the urine of quetiapine patients and can result in apparent adherence rates that are improved relative to those determined using only quetiapine and 7-hydroxyquetiapine. For example, analysis of a random set of 114 patients who were prescribed quetiapine exhibited an apparent adherence rate of 47% using the quetiapine carboxylic acid and quetiapine sulfoxide metabolites. Traditional metabolite testing with quetiapine and 7-hydroxyquetiapine yielded apparent adherence rates of ~31% while all four analytes resulted in apparent adherence of 48%. The prevalence of these metabolites suggests that quetiapine urine drug testing would be more consistent with prescriptions when they are included in the analysis.
authors: Ameritox, Ltd, Research and Development Department, 486 Gallimore Dairy Rd, Greensboro, NC 27409, USA erin.strickland@ameritox.com.
authors: Erin C
authors: EC
authors: Strickland
authors: Ameritox, Ltd, Research and Development Department, 486 Gallimore Dairy Rd, Greensboro, NC 27409, USA.
authors: Oneka T
authors: OT
authors: Cummings
authors: Ameritox, Ltd, Research and Development Department, 486 Gallimore Dairy Rd, Greensboro, NC 27409, USA.
authors: Ayodele A
authors: AA
authors: Morris
authors: Ameritox, Ltd, Research and Development Department, 486 Gallimore Dairy Rd, Greensboro, NC 27409, USA.
authors: Alexandra
authors: A
authors: Clinkscales
authors: Ameritox, Ltd, Research and Development Department, 486 Gallimore Dairy Rd, Greensboro, NC 27409, USA.
authors: Gregory L
authors: GL
authors: McIntire
mesh_terms: D014150:Antipsychotic Agents / Q000008:administration & dosage* / Q000652:urine; D002264:Carboxylic Acids / Q000652:urine*; D002853:Chromatography, Liquid; D004305:Dose-Response Relationship, Drug; D016903:Drug Monitoring; D006801:Humans; D057230:Limit of Detection; D055118:Medication Adherence; D000069348:Quetiapine Fumarate / Q000008:administration & dosage / Q000652:urine*; D015203:Reproducibility of Results; D013048:Specimen Handling; D013454:Sulfoxides / Q000652:urine*; D053719:Tandem Mass Spectrometry
chemical_list: D014150:Antipsychotic Agents; D002264:Carboxylic Acids; D013454:Sulfoxides; D000069348:Quetiapine Fumarate