title: Pharmacokinetics of penicillin G procaine versus penicillin G potassium and procaine hydrochloride in horses.
abstract: OBJECTIVE
  To compare the pharmacokinetics of penicillin G and procaine in racehorses following i.m. administration of penicillin G procaine (PGP) with pharmacokinetics following i.m. administration of penicillin G potassium and procaine hydrochloride (PH).
  
  
  METHODS
  6 healthy adult mares.
  
  
  METHODS
  Horses were treated with PGP (22,000 units of penicillin G/kg of body weight, i.m.) and with penicillin G potassium (22,000 U/kg, i.m.) and PH (1.55 mg/kg, i.m.). A minimum of 3 weeks was allowed to elapse between drug treatments. Plasma and urine penicillin G and procaine concentrations were measured by use of high-pressure liquid chromatography.
  
  
  RESULTS
  Median elimination phase half-lives of penicillin G were 24.7 and 12.9 hours, respectively, after administration of PGP and penicillin G potassium. Plasma penicillin G concentration 24 hours after administration of penicillin G potassium and PH was not significantly different from concentration 24 hours after administration of PGP. Median elimination phase half-life of procaine following administration of PGP (15.6 hours) was significantly longer than value obtained after administration of penicillin G potassium and PH (1 hour).
  
  
  CONCLUSIONS
  Results suggest that i.m. administration of penicillin G potassium will result in plasma penicillin G concentrations for 24 hours after drug administration comparable to those obtained with administration of PGP Clearance of procaine from plasma following administration of penicillin G potassium and PH was rapid, compared with clearance following administration of PGP.
authors.affiliation: West Chester University, Department of Chemistry, PA 19382, USA.
authors.forename: C E
authors.initials: CE
authors.lastname: Uboh
authors.forename: L R
authors.initials: LR
authors.lastname: Soma
authors.forename: Y
authors.initials: Y
authors.lastname: Luo
authors.forename: E
authors.initials: E
authors.lastname: McNamara
authors.forename: M A
authors.initials: MA
authors.lastname: Fennell
authors.forename: L
authors.initials: L
authors.lastname: May
authors.forename: D C
authors.initials: DC
authors.lastname: Teleis
authors.forename: J A
authors.initials: JA
authors.lastname: Rudy
authors.forename: A O
authors.initials: AO
authors.lastname: Watson
mesh_terms: D000818:Animals; D019540:Area Under Curve; D002851:Chromatography, High Pressure Liquid / Q000662:veterinary; D005260:Female; D006207:Half-Life; D006736:Horses / Q000378:metabolism*; D007273:Injections, Intramuscular / Q000662:veterinary; D016018:Least-Squares Analysis; D010402:Penicillin G Procaine / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics* / Q000652:urine; D010406:Penicillins / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics* / Q000652:urine; D018709:Statistics, Nonparametric
chemical_list: D010406:Penicillins; D010402:Penicillin G Procaine