title: Effect of thioridazine on phenytoin serum concentration: a retrospective study.
abstract: Serum phenytoin concentrations before and after the addition of thioridazine were retrospectively compared in 27 adults to determine if an interaction occurred between these two drugs. A change in the serum phenytoin concentration of +/- 4 micrograms/ml was considered clinically significant; by this definition four patients (14.8 percent) had an increase, two (7.4 percent) had a decrease, and most (77.8 percent) demonstrated no change. The mean difference was 0.8 microgram/ml +/- 3.7 micrograms/ml and was not found to be statistically significant (p less than 0.1). Clinically important alterations in phenytoin serum concentration as caused by thioridazine appear to be infrequent.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D004347:Drug Interactions; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010672:Phenytoin / Q000097:blood*; D012189:Retrospective Studies; D013881:Thioridazine / Q000009:adverse effects*
chemical_list: D010672:Phenytoin; D013881:Thioridazine