Krantz et al. (A-12) investigated dose-related effects of methadone in subjects with torsade de pointes, a polymorphic ventricular tachycardia. In the study of 17 subjects, nine were being treated with methadone for opiate dependency and eight for chronic pain. The mean daily dose of methadone in the opiate dependency group was 541 mg/day with a standard deviation of 156, while the chronic pain group received a mean dose of 269 mg/day with a standard deviation of 316.