Clinical pharmacology of clemastine in healthy dogs.
The pharmacokinetic properties of clemastine were investigated in six healthy dogs and compared with the effect of the drug recorded as inhibition of wheal formation induced by intradermal injections of histamine. Clemastine clearance was high (median: 2.1 L h(-1) kg(-1)) and the volume of distribution large (13.4 L kg(-1)). The half-life after intravenous administration was 3.8 h and the plasma protein binding level in vitro was 98%. After oral administration, the bioavailability was only 3%. Given intravenously, clemastine (0.1 mg kg(-1)) inhibited wheal formation completely for 7 h, whereas the effect after oral administration (0.5 mg kg(-1)) was minor. The data show that most dosage regimens suggested in the literature for the oral administration of clemastine to dogs are likely to give too low a systemic exposure of the drug to allow effective therapy.
Hansson
H
H
Department of Small Animal Clinical Sciences, Box 7037, Swedish University of Agricultural Sciences, S-750 07 Uppsala, Sweden. Helene.Hansson@kirmed.slu.se
Bergvall
K
K
Bondesson
U
U
Hedeland
M
M
Törneke
K
K
D000284:Administration, Oral; D000818:Animals; D019540:Area Under Curve; D001682:Biological Availability; D002974:Clemastine / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics* / Q000627:therapeutic use*; D018592:Cross-Over Studies; D004283:Dog Diseases / Q000139:chemically induced / Q000517:prevention & control*; D004285:Dogs / Q000378:metabolism*; D005260:Female; D006632:Histamine; D006634:Histamine H1 Antagonists / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics* / Q000627:therapeutic use*; D006967:Hypersensitivity / Q000209:etiology / Q000517:prevention & control / Q000662:veterinary*; D007275:Injections, Intravenous / Q000662:veterinary
D006634:Histamine H1 Antagonists; D006632:Histamine; D002974:Clemastine