Pharmacokinetics of potassium bromide in adult horses.

The research explores the impact of potassium bromide on adult horses, looking at single and multiple dose pharmacokinetics. The results indicate that with appropriate dosing, the use of potassium bromide could potentially manage seizures in horses, similar to other species, hence the need for further studies to verify its effectiveness as an anticonvulsant medication.

Research and Methodology

• The study involved twelve adult mares from the Standardbred and Thoroughbred breeds. The horses were divided into two groups, with each group subjected to a different treatment regimen involving potassium bromide, a common drug used in the management of seizures.
• Group 1 horses were given a single oral dose of 120 mg/kg of potassium bromide.
• In part two of the study, horses were given 120 mg/kg of potassium bromide daily for a period of 5 days, followed by a daily maintenance dose of 40 mg/kg in their feed for a period of 7 days.
• The research team measured serum concentrations of potassium bromide to create concentration versus time curves. They also calculated various pharmacokinetic parameters to understand more accurately how horses metabolize this drug.

Observations and Results

• The average maximum serum concentration following a single dose of potassium bromide was 423 +/- 22 microg/mL, with an average elimination half-life of approximately 75 +/- 14 hours.
• The research found that administering a loading dose of KBr (120 mg/kg once daily for 5 days), led to a maximum average serum concentration of 1639 +/- 156 microg/mL.
• When horses were given lower, maintenance doses (40 mg/kg once daily), there was a decrease in serum bromide concentrations, which eventually plateaued at about 1000 microg/mL.
• Important but fleeting changes were observed in serum potassium and sodium concentrations following the administration of KBr. Potential alterations were also found in base excess and plasma bicarbonate concentrations.
• Higher serum concentrations of bromide were observed to increase serum chloride concentrations when measured on an ion-specific electrode.

Conclusion and Implications

• The findings suggest that loading doses of 120 mg/kg daily over 5 days, followed by maintenance doses of about 90 mg/kg of KBr delivered once daily, can achieve serum bromide concentrations that could potentially manage seizures in horses, mirroring the use of the drug in other species.
• Despite these promising inferences, more investigation is required to establish the effectiveness of potassium bromide as an anticonvulsant medication and calmative for horses.