title: Pharmacokinetics of oral pimobendan in healthy cats.
abstract: OBJECTIVE
  To describe the pharmacokinetics of oral pimobendan in healthy cats.
  
  
  METHODS
  18 purpose-bred cats.
  
  
  METHODS
  In 10 cats, blood samples were collected before, and at multiple time points after, a single oral dose of pimobendan (0.28 ± 0.04 mg/kg). In 8 cats, blood samples were collected at 3 various time points on the first and third days of twice daily oral dosing of pimobendan for a total of 7 doses (0.31 ± 0.04 mg/kg). Plasma concentrations of pimobendan were quantified by high pressure liquid chromatography coupled to tandem mass spectrometry.
  
  
  RESULTS
  A 1-compartment open model with first order absorption in and elimination from the central compartment with a lag time best describes the disposition of pimobendan. Two cats were removed from final pharmacokinetic descriptive analysis due to delayed minimal absorption from gastrointestinal adverse effects. After a lag time (0.3 ± 0.06 h), pimobendan was rapidly absorbed (absorption half-life = 0.2 ± 0.08 h) and eliminated (elimination half-life = 1.3 ± 0.2 h). Maximum plasma concentrations (34.50 ± 6.59 ng/mL) were high and were predicted 0.9 h after drug administration. Apparent volume of distribution at steady state (per bioavailability) was large (8.2 ± 2.5 L/kg). The multi-dose study showed the pharmacokinetic model to be robust.
  
  
  CONCLUSIONS
  When administered a similar dose on a per weight basis, pimobendan has a substantially longer elimination half-life and maximal drug plasma concentration in cats as compared to those previously reported in dogs.
authors.affiliation: Department of Clinical Sciences, Kansas State University, 1800 Denison Ave., Manhattan, KS 66506, USA. andrew.hanzlicek@okstate.edu
authors.forename: Andrew S
authors.initials: AS
authors.lastname: Hanzlicek
authors.forename: Ronette
authors.initials: R
authors.lastname: Gehring
authors.forename: Butch
authors.initials: B
authors.lastname: Kukanich
authors.forename: Kate S
authors.initials: KS
authors.lastname: Kukanich
authors.forename: Michele
authors.initials: M
authors.lastname: Borgarelli
authors.forename: Nicole
authors.initials: N
authors.lastname: Smee
authors.forename: Emily E
authors.initials: EE
authors.lastname: Olson
authors.forename: Marco
authors.initials: M
authors.lastname: Margiocco
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001682:Biological Availability; D002316:Cardiotonic Agents / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D002415:Cats / Q000097:blood / Q000378:metabolism*; D004334:Drug Administration Schedule; D005260:Female; D006207:Half-Life; D008297:Male; D010865:Pilot Projects; D011724:Pyridazines / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D013997:Time Factors
chemical_list: D002316:Cardiotonic Agents; D011724:Pyridazines; C041648:pimobendan