Pharmacokinetics of dantrolene sodium in horses.

The research article studies the pharmacokinetics of dantrolene sodium in horses, investigating its distribution and elimination after intravenous and intragastric administration.

Objective of the Research

• This research aimed to understand the way horses absorb, distribute, metabolize, and excrete dantrolene sodium; a muscle relaxation drug commonly used in medicine. It involved both intravenous (IV) and intragastric (IG) administration of the drug, which helps in determining its effectiveness and dosage guidelines.

Study Design and Participants

• The research involved administering the drug to horses, with both IV and IG routes being used. The dosage was 2 mg/kg for intravenous and 4 mg/kg for intragastric administrations.
• Additionally, two ponies received an intravenous dose of the drug in a pilot study, providing preliminary kinetic data and helping in the assessment of urinary and biliary excretion of the medication.

Findings from the Research

• The results showed that the distribution and elimination of dantrolene were rapid in horses, with an elimination half-life of approximately 129 minutes and a whole-body clearance rate of around 4.16 ml/min/kg.
• After intragastric administration, the peak concentration of dantrolene was achieved rapidly, within 1.5 hours. However, absorption was incomplete, resulting in a bioavailability of around 39%.
• Only small quantities of the intact drug were recovered in urine and bile, suggesting most of the medication was metabolized.

Implication of the Findings

• The findings from this research are crucial as they help establish dosage guidelines for veterinary application of dantrolene sodium, aiming to maintain the blood concentration of the drug within the predicted clinically effective range.