*Schools of Medicine & Biomedical Sciences, University of Western Australia, Crawley, Western Australia, Australia;

†Clinical Pharmacology & Toxicology, PathWest Laboratory Medicine, Nedlands, Western Australia, Australia;

‡Medical School, University of Western Australia, Crawley, Western Australia, Australia;

§Fremantle Hospital Mental Health Service, Fremantle, Western Australia, Australia;

¶Department of Pharmacy, Graylands Hospital, Mount Claremont, Western Australia, Australia; and

║Department of Clinical Pharmacology, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia.

Correspondence: David A Joyce, MBBS, MD, FRACP, School of Medicine & School of Biomedical Sciences, University of Western Australia, Room G15A, “M” Block, QEII Medical Centre, Nedlands, WA, Australia, 6009 (e-mail: [email protected]).

Supported by contributions in kind from the PathWest Laboratory Medicine and the West Australian Department of Health.

All authors declare no conflicts of interest.

Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal's Web site (www.drug-monitoring.com).

M. Berneri and U. Jha have contributed equally.

M. Berneri and U. Jha organized and carried out data collection and contributed to study design. S. O'Halloran supervised clozapine and N-desmethylclozapine measurements and contributed to data organization and analysis. S. Salman contributed to data analysis and provided expert advice on population pharmacokinetic analyses. S. Wickramasinghe and K. Kendrick collected data and contributed to study design. J. Nguyen assisted with data collection and database access. D. A. Joyce contributed to the design, organization, ethics approval applications, data organization, and data analysis. All authors participated in discussions and in manuscript preparation.