title: Pharmacokinetics of controlled-release carbimazole tablets support once daily dosing in cats.
abstract: Carbimazole, a prodrug of methimazole, is used in the treatment of hyperthyroidism in cats. The pharmacokinetics of methimazole was investigated in healthy cats following oral administration of 15 mg of carbimazole as a controlled-release tablet (Vidalta), Intervet). The controlled-release tablet did not produce a pronounced concentration peak and methimazole was present in the circulation for a sustained period, compared with a conventional tablet formulation. The time to reach peak concentrations after carbimazole administration was quite long (t(max) 6 h). The absolute bioavailability of carbimazole was around 88 +/- 11%. Repeated oral administration daily for 13 consecutive days did not lead to accumulation of methimazole in plasma. The extent of absorption of carbimazole was about 40% higher when administered to cats that had been fed compared to fasted cats. The relative oral bioavailability of methimazole following administration of the controlled-release tablets was similar to that of a conventional release formulation (83 +/- 21%). The pharmacokinetics of this controlled-release formulation of carbimazole supports its use as a once daily treatment (both as a starting dose and for maintenance therapy) for cats with hyperthyroidism.
authors.affiliation: Intervet Pharma R&D, Beaucouzé, France.
authors.forename: R
authors.initials: R
authors.lastname: Frénais
authors.forename: S
authors.initials: S
authors.lastname: Burgaud
authors.forename: L J I
authors.initials: LJ
authors.lastname: Horspool
mesh_terms: D000284:Administration, Oral; D000818:Animals; D013956:Antithyroid Agents / Q000097:blood / Q000378:metabolism / Q000493:pharmacokinetics*; D019540:Area Under Curve; D001682:Biological Availability; D002231:Carbimazole / Q000378:metabolism / Q000493:pharmacokinetics*; D002415:Cats; D002626:Chemistry, Pharmaceutical; D003692:Delayed-Action Preparations; D005215:Fasting / Q000378:metabolism; D005260:Female; D008297:Male; D008713:Methimazole / Q000097:blood* / Q000378:metabolism / Q000493:pharmacokinetics
chemical_list: D013956:Antithyroid Agents; D003692:Delayed-Action Preparations; D008713:Methimazole; D002231:Carbimazole