title: Pharmacokinetics and physiologic effects of alprazolam after a single oral dose in healthy mares.
abstract: The objective of this study was to evaluate the pharmacokinetic properties and physiologic effects of a single oral dose of alprazolam in horses. Seven adult female horses received an oral administration of alprazolam at a dosage of 0.04 mg/kg body weight. Blood samples were collected at various time points and assayed for alprazolam and its metabolite, α-hydroxyalprazolam, using liquid chromatography/mass spectrometry. Pharmacokinetic disposition of alprazolam was analyzed by a one-compartmental approach. Mean plasma pharmacokinetic parameters (±SD) following single-dose administration of alprazolam were as follows: Cmax 14.76 ± 3.72 ng/mL and area under the curve (AUC0-∞ ) 358.77 ± 76.26 ng·h/mL. Median (range) Tmax was 3 h (1-12 h). Alpha-hydroxyalprazolam concentrations were detected in each horse, although concentrations were low (Cmax 1.36 ± 0.28 ng/mL). Repeat physical examinations and assessment of the degree of sedation and ataxia were performed every 12 h to evaluate for adverse effects. Oral alprazolam tablets were absorbed in adult horses and no clinically relevant adverse events were observed. Further evaluation of repeated dosing and safety of administration of alprazolam to horses is warranted.
authors.affiliation: Department of Veterinary Clinical Sciences, Lloyd Veterinary Medical Center, College of Veterinary Medicine, Iowa State University, Ames, IA, USA.
authors.forename: D M
authors.initials: DM
authors.lastname: Wong
authors.forename: J L
authors.initials: JL
authors.lastname: Davis
authors.forename: C J
authors.initials: CJ
authors.lastname: Alcott
authors.forename: K L
authors.initials: KL
authors.lastname: Hepworth-Warren
authors.forename: N L
authors.initials: NL
authors.lastname: Galow-Kersh
authors.forename: S
authors.initials: S
authors.lastname: Rice
authors.forename: J F
authors.initials: JF
authors.lastname: Coetzee
mesh_terms: D000284:Administration, Oral; D000525:Alprazolam / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000097:blood / Q000493:pharmacokinetics* / Q000494:pharmacology; D000818:Animals; D001259:Ataxia / Q000139:chemically induced / Q000662:veterinary; D016292:Procedural Sedation / Q000379:methods / Q000662:veterinary; D005260:Female; D006736:Horses / Q000378:metabolism*; D006993:Hypnotics and Sedatives / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics* / Q000494:pharmacology
chemical_list: D006993:Hypnotics and Sedatives; C032318:alpha-hydroxyalprazolam; D000525:Alprazolam