Pharmacokinetics of a single, orally administered dose of digoxin in horses.

The research study tests the effects of administering a single oral dose of the drug digoxin on horses, how their bodies absorb, metabolize, and excrete it over time.

Methodology

• The researchers conducted this study on a group of healthy horses of diverse breeds and sexes.
• The horses received a single dose of digoxin elixir, specifically 0.022 mg/kg, via a stomach tube, a common method to deliver medication to horses.

Findings

• The researchers discovered that the maximum serum concentration of digoxin, 2.21 +/- 0.6 ng/ml, was reached about one hour after administering the medication.
• The half-life of digoxin, which is the time it takes for the concentration to diminish by half in the body of horses, was approximately 28.8 +/- 10.7 hours.
• They found out that the pharmacokinetics of digoxin follows a triexponential curve, implying a two-compartmental model is necessary to represent the pattern of its concentration over time after oral administration.
• They also calculated that to achieve the average serum concentration of digoxin of 1.1 ng/ml, a daily oral dose of 17.4 micrograms of digoxin elixir and an IV dose of 6.1 micrograms of parenteral preparation per kg of body weight of the horse would be needed.

Impact on Vital Parameters

• The study also looked into the possible effects of digoxin on horses’ vital parameters such as base-line serum calcium, potassium, sodium concentrations, heart rate, P-R interval (measures the time from the beginning of electrical conduction through the heart to the beginning of the ventricles contraction), and mean arterial blood pressure.
• The results showed no significant change in any of these parameters after administering digoxin, with a P-value greater than 0.05, indicating that the changes could easily have been due to chance rather than the administered drug.

Conclusion

• This research provides valuable data about the pharmacokinetic properties of the drug digoxin in horses.
• It also lays out meaningful insights that inform dosage guidelines to achieve desired average serum concentrations of the drug.