title: Evaluating a possible pharmacokinetic interaction between remifentanil and esmolol in the rat.
abstract: Remifentanil (Ultiva) is a novel, ultra-short-acting opioid which has recently been approved for use as an analgesic during induction and maintenance of general anesthesia. Esmolol is a short-acting beta-blocker used during surgical procedures to reduce heart rate and blood pressure. Both drugs are metabolized by nonspecific esterases in the blood and other tissues and may be administered concomitantly during surgery. The goal of this study was to determine if coadministration of esmolol significantly alters the pharmacokinetics of remifentanil in the rat. Two groups of rats were dosed with remifentanil [25 micrograms/kg/min (n = 8)] and remifentanil plus esmolol [25 and 200 mg/kg/min (n = 7)] for 20 min. Cardiovascular measurements were collected continuously over the course of the study. Serial blood samples (12) were collected over 25 min into test tubes containing 0.5 mL of acetonitrile. Blood samples were extracted (liquid-liquid) with methylene chloride and then analyzed by a validated GC-MS assay. Compartmental data analysis was performed using PCNONLIN. The mean(+/- SD) for Cl and t1/2 observed in treatment I were 390(+/- 98) mL/min/kg and 0.69(+/- 0.27) min and in treatment II were 421(+/- 164) mL/min/kg and 0.56(+/- 0.22) min, respectively. Comparison of clearance, volume of distribution, and terminal half-life between the two groups showed that coadministration of esmolol had no significant (p < 0.05) effect on the pharmacokinetics of remifentanil in the rat.
authors.affiliation: Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore 21201, USA.
authors.forename: S H
authors.initials: SH
authors.lastname: Haidar
authors.forename: J E
authors.initials: JE
authors.lastname: Moreton
authors.forename: Z
authors.initials: Z
authors.lastname: Liang
authors.forename: J F
authors.initials: JF
authors.lastname: Hoke
authors.forename: K T
authors.initials: KT
authors.lastname: Muir
authors.forename: N D
authors.initials: ND
authors.lastname: Eddington
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000701:Analgesics, Opioid / Q000493:pharmacokinetics*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D004347:Drug Interactions; D006339:Heart Rate / Q000187:drug effects; D008297:Male; D008954:Models, Biological; D010880:Piperidines / Q000493:pharmacokinetics* / Q000494:pharmacology; D011412:Propanolamines / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D000077208:Remifentanil
chemical_list: D000319:Adrenergic beta-Antagonists; D000701:Analgesics, Opioid; D010880:Piperidines; D011412:Propanolamines; C036604:esmolol; D000077208:Remifentanil