title: Finasteride, a steroid 5 alpha-reductase inhibitor, does not affect the oxidative metabolism of antipyrine.
abstract: A single-blind study was conducted to investigate the effect of multiple doses of finasteride, a 5 alpha-reductase inhibitor for the treatment of benign prostatic hyperplasia, on the single-dose pharmacokinetics of antipyrine. Twelve patients with benign prostatic hyperplasia received a total of four single oral doses of 18 mg/kg antipyrine before, during, and after treatment with 10 mg/day of finasteride for 28 days. Finasteride had no effect on antipyrine concentration profiles. There were also no changes in urinary excretion of three principal antipyrine metabolites. A slight increase in renal clearance of antipyrine was observed; however, this is not considered relevant because excretion of unchanged antipyrine represents a minor fraction of total elimination and is not directly related to oxidative metabolism. These results imply that significant interactions between finasteride and drugs metabolized by these cytochrome P-450 enzymes are unlikely.
authors.affiliation: Merck Sharp & Dohme Research Laboratories, West Point, PA 19486.
authors.forename: G A
authors.initials: GA
authors.lastname: Winchell
authors.forename: S
authors.initials: S
authors.lastname: Gregoire
authors.forename: A M
authors.initials: AM
authors.lastname: Taylor
authors.forename: J
authors.initials: J
authors.lastname: Hegland
authors.forename: D B
authors.initials: DB
authors.lastname: Hunninghake
mesh_terms: D000284:Administration, Oral; D000368:Aged; D000983:Antipyrine / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D018120:Finasteride / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008875:Middle Aged; D011470:Prostatic Hyperplasia / Q000188:drug therapy*; D016037:Single-Blind Method
chemical_list: D018120:Finasteride; D000983:Antipyrine