title: Pharmacokinetic/pharmacodynamic relationship of eptazocine, a narcotic-antagonist analgesic, in rats.
abstract: The relationship between the pharmacokinetics and the pharmacodynamics of eptazocine, a narcotic-antagonist analgesic, was investigated in rats. The analgesic effect of eptazocine (2.5, 5 and 10 mg/kg) following intravenous (i.v) administration was evaluated by both the Randall-Selitto method and the D'Amour-Smith method. The analgesic effects were determined before and at designed intervals for a period of 120 min after eptazocine administration, and are expressed as area under the effect-time curve (AUC(E)). The plasma concentration of eptazocine was determined by fluorescence HPLC and was analyzed with a two compartment open model using the nonlinear least-squares method. Eptazocine produced a dose-dependent analgesic effect. It was demonstrated that eptazocine has a linear relationship between AUC(E) and the area under the plasma concentration-time curve (AUC) following i.v. administration for three different doses ranging from 2.5 to 10 mg/kg.
authors.affiliation: Department of Pharmaceutics, College of Pharmacy, Nihon University, Funabashi, Chiba, Japan. t-suzuki@pha.nihon-u.ac.jp
authors.forename: T
authors.initials: T
authors.lastname: Suzuki
authors.forename: R
authors.initials: R
authors.lastname: Shimizu
authors.forename: T
authors.initials: T
authors.lastname: Suganuma
authors.forename: J
authors.initials: J
authors.lastname: Nishino
authors.forename: K
authors.initials: K
authors.lastname: Tomono
authors.forename: M
authors.initials: M
authors.lastname: Hanano
authors.forename: J
authors.initials: J
authors.lastname: Watanabe
mesh_terms: D000700:Analgesics / Q000097:blood / Q000493:pharmacokinetics* / Q000494:pharmacology*; D000818:Animals; D019540:Area Under Curve; D003496:Cyclazocine / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics* / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D009292:Narcotic Antagonists / Q000097:blood / Q000493:pharmacokinetics / Q000494:pharmacology; D009619:Nociceptors / Q000187:drug effects; D010147:Pain Measurement / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar
chemical_list: D000700:Analgesics; D009292:Narcotic Antagonists; C033776:eptazocine; D003496:Cyclazocine