Species differences in the pharmacokinetics of recainam, a new anti-arrhythmic drug

✍ Scribed by J. A. Scatina; H. B. Kimmel; V. Weinstein; S. M. Troy; S. F. Sisenwine; M. N. Cayen

• Publisher: John Wiley and Sons
• Year: 1990
• Tongue: English
• Weight: 774 KB
• Volume: 11
• Category: Article
• ISSN: 0142-2782
• DOI: 10.1002/bdd.2510110508

✦ Synopsis

Abstract

The pharmacokinetics of recainam, an anti‐arrhythmic drug, were compared in mice, rats, rabbits, dogs, rhesus monkeys, and man, Bioavailability was virtually complete in monkeys and dogs, 67 per cent in man and 51 per cent in rats. Non‐linear kinetics between the oral and i.v. dose in rabbits precluded estimation of bioavailability. Linear plasma dose proportionality occurred in dogs between 6 and 60 mgkg^−1^ oral doses and rhesus monkeys between 1 and 15 mgkg^−1^ i.v. doses. A greater than proportional increase in the plasma AUC of recainam occurred between oral doses ranging from 54–208 mg kg^−1^ in mice, 25–110 mg kg^−1^ in rats, and 50–100 mg kg^−1^ in rabbits. In human subjects, the AUC/unit dose was linear between 400 and 800 mg. The terminal elimination t~1/2~ of recainam ranged from 1–5 h in laboratory animals and man. The plasma C~max~ and AUC of recainam were virtually identical after single or multiple (21 day) oral doses in dogs. After an i.v. dose, plasma clearance of recainam (1 kg^−1^. h) was 4·9–5·2 in rats and rabbits and 0·4–1·9 in dogs, rhesus monkeys, and man. The steady state volume of distribution was 2–5 times larger than the total body water of laboratory animals and man. Recainam was very poorly bound (10–45 per cent) to the serum proteins of rodents, rabbits, dogs, rhesus monkeys and man. In rhesus monkeys and man, recainam accounted for 10 per cent and 70 per cent, respectively, of the plasma radioactivity at 6h post‐dose. The pharmacokinetic profile of recainam in dogs most closely resembled that of man.