1. Department of Pharmacotherapy, College of Pharmacy, University of Utah, Salt Lake City.
2. Center for Health Outcomes and PharmacoEconomic Research, College of Pharmacy, The University of Arizona, Tucson.
3. College of Pharmacy, University of Utah, Salt Lake City.
4. Otsuka Pharmaceutical Development & Commercialization, Inc., Princeton, NJ (Waters), at the time the study was conducted.