Quetiapine, Misuse and Dependency: A Case-Series of Questions to a Norwegian Network of Drug Information Centers.

Purpose: The second-generation antipsychotic quetiapine has been associated with misuse and dependency. We aimed to review questions to the Norwegian network of drug information centers concerning this potential drug safety problem.

Methods: We conducted a Boolean search in the database of the Regional Medicines Information and Pharmacovigilance Centres in Norway (RELIS) combining the indexed categories "quetiapine" and "adverse drug reaction" with the text words "misuse" or "dependency". Question-answer pairs (Q/As) in the full-text, searchable RELIS database were defined as cases. Cases were analyzed for drug safety issues linked to use of quetiapine, including off-label use, polypharmacy and other patient risk factors.

Results: The search resulted in 54 cases. Forty-six cases (85%) were patient-related, and a majority came from physicians working in hospitals. Twenty-nine cases (54%) concerned patients with a history of addiction, 14 cases (26%) had polypharmacy, and off-label use of quetiapine for insomnia was identified in 14 of the cases (26%). Only three of the cases included a specific question about patient dependency of quetiapine, and these cases were all associated with insomnia.

Conclusion: We conclude that our case series from the Norwegian network of drug information centres reflects that quetiapine frequently involves clinical narratives of a history of addiction, polypharmacy or insomnia (off-label use). However, the case series did not reveal new information about the drug's addictive potential.