title: Pharmacokinetics and cardiovascular effects following a single oral administration of a nonaqueous pimobendan solution in healthy dogs.
abstract: Pimobendan is an inodilator used in the treatment of canine congestive heart failure (CHF). The aim of this study was to investigate the pharmacokinetics and cardiovascular effects of a nonaqueous oral solution of pimobendan using a single-dose, operator-blinded, parallel-dose study design. Eight healthy dogs were divided into two treatment groups consisting of water (negative control) and pimobendan solution. Plasma samples and noninvasive measures of cardiovascular function were obtained over a 24-h period following dosing. Pimobendan and its active metabolite were quantified using an ultra-high-performance liquid chromatography-mass spectrometer (UHPLC-MS) assay. The oral pimobendan solution was rapidly absorbed [time taken to reach maximum concentration (Tmax ) 1.1 h] and readily converted to the active metabolite (metabolite Tmax 1.3 h). The elimination half-life was short for both pimobendan and its active metabolite (0.9 and 1.6 h, respectively). Maximal cardiovascular effects occurred at 2-4 h after a single oral dose, with measurable effects occurring primarily in echocardiographic indices of systolic function. Significant effects persisted for <8 h. The pimobendan nonaqueous oral solution was well tolerated by study dogs.
authors.affiliation: University Veterinary Teaching Hospital, Faculty of Veterinary Science, University of Sydney, Sydney, NSW, Australia.
authors.forename: M
authors.initials: M
authors.lastname: Yata
authors.affiliation: Faculty of Pharmacy, University of Sydney, Sydney, NSW, Australia.
authors.forename: A J
authors.initials: AJ
authors.lastname: McLachlan
authors.affiliation: School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, South Australia, Australia.
authors.forename: D J R
authors.initials: DJ
authors.lastname: Foster
authors.affiliation: Luoda Pharma, Caringbah, NSW, Australia.
authors.forename: S W
authors.initials: SW
authors.lastname: Page
authors.affiliation: University Veterinary Teaching Hospital, Faculty of Veterinary Science, University of Sydney, Sydney, NSW, Australia.
authors.forename: N J
authors.initials: NJ
authors.lastname: Beijerink
mesh_terms: D000284:Administration, Oral; D000818:Animals; D019540:Area Under Curve; D004285:Dogs; D005260:Female; D006207:Half-Life; D008297:Male; D011724:Pyridazines / Q000008:administration & dosage / Q000493:pharmacokinetics*; D014665:Vasodilator Agents / Q000008:administration & dosage / Q000493:pharmacokinetics*
chemical_list: D011724:Pyridazines; D014665:Vasodilator Agents; C041648:pimobendan