Dose-dependent plasma elimination of subcutaneously administered calcium heparin in horses.

The research paper presents a study on the pharmacokinetic parameters of subcutaneously injected low dose heparin in horses, showing how different doses affect plasma concentrations and plasma elimination of the drug.

Study Design

• The experiment used four groups of five horses each and one group of eleven horses. All horses were mature and healthy, belonging to different breeds.
• Each group was given a single subcutaneous injection of a specific dose of calcium heparin based on their body weight. The doses ranged from 60 to 150 units per kg of body weight. These injections were administered in the pectoral region of each horse.
• In order to measure heparin concentrations in the horses’ plasma, blood samples were taken from the horses’ jugular vein before the injection and then at hourly intervals for 12 hours after the injection.

Findings

• The study found that peak concentrations of heparin in the plasma occurred around 4 hours after the injection. The concentration varied based on the dose administered, with higher doses leading to higher peak concentrations.
• Data from the groups given 60 and 100 units per kg could not be used for kinetic calculations due to undisclosed reasons.
• The study also provided data on the elimination constant (l/h), half-life (h), and total elimination time (h) for the doses of 80, 125, and 150 units per kg. These values indicate the rate at which the heparin was removed from the horses’ bodies.
• The elimination times to reach baseline values after administration were found to increase with higher dosage.
• After 12 hours, the calculated heparin concentrations for doses of 80, 125, and 150 units per kg were still present but significantly reduced.

Implications

• This research provides valuable data concerning the effect of different doses of subcutaneously administered calcium heparin on its plasma elimination in horses.
• The findings can be utilized for better therapeutic decision making concerning anticoagulant administration in horses, and potentially in other large animals.
• The study highlights the importance of considering dosage and body weight when calculating the most effective and safe application of a medication such as heparin. This could contribute to veterinary best practices and guidelines in the future.