title: Pharmacokinetics of potassium bromide in adult horses.
abstract: OBJECTIVE
  To determine the pharmacokinetics of potassium bromide (KBr) in horses after single and multiple oral doses.
  
  
  METHODS
  Twelve adult Standardbred and Thoroughbred mares.
  
  
  METHODS
  Horses were randomly assigned to two treatment groups. Group 1 horses were given a single oral dose of 120 mg/kg potassium bromide. Part 2 of the study evaluated a loading dose of 120 mg/kg KBr daily by stomach tube for 5 days, followed by 40 mg/kg daily in feed for 7 days. Serum concentrations of KBr were measured to construct concentration versus time curves and to calculate pharmacokinetic parameters. Treated horses were monitored twice daily by clinical examination. Serum concentrations of sodium, potassium and chloride ions and partial pressures of venous blood gases were determined.
  
  
  RESULTS
  Maximum mean serum concentration following a single dose of KBr (120 mg/kg) was 423 +/- 22 microg/mL and the mean elimination half-life was 75 +/- 14 h. Repeated administration of a loading dose of KBr (120 mg/kg once daily for 5 d) gave a maximum serum concentration 1639 +/- 156 microg/mL. The administration of lower, maintenance doses (40 mg/kg once daily) was associated with decreased serum bromide concentrations, which plateaued at approximately 1000 microg/mL. Administration of KBr was associated with significant but transient changes in serum potassium and sodium concentrations, and possible changes in base excess and plasma bicarbonate concentrations. High serum concentrations of bromide were associated with an apparent increase in serum chloride concentrations, when measured on an ion specific electrode.
  
  
  CONCLUSIONS
  and clinical relevance Loading doses of 120 mg/kg daily over 5 d and maintenance doses of approximately 90 mg/kg of KBr administered once daily resulted in serum bromide concentrations consistent with therapeutic efficacy for the management of seizures in other species. The clinical efficacy of this agent as an anticonvulsant medication and/or calmative in horses warrants further investigation.
authors: Division of Veterinary and Biomedical Sciences, Murdoch University, South Street, Murdoch, Western Australia.
authors: S L
authors: SL
authors: Raidal
authors: S
authors: S
authors: Edwards
mesh_terms: D000284:Administration, Oral; D000818:Animals; D000927:Anticonvulsants / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D001965:Bromides / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D004334:Drug Administration Schedule; D005260:Female; D006736:Horses / Q000378:metabolism*; D017680:Potassium Compounds / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D016896:Treatment Outcome
chemical_list: D000927:Anticonvulsants; D001965:Bromides; D017680:Potassium Compounds; C039004:potassium bromide