[The treatment basis for anticoagulants in horses].

The research article investigates the pharmacokinetics of racemic phenprocoumon in horses, given both orally and intravenously, and its effect on the coagulation system. The authors established its effectiveness as a potential long-term anticoagulant for horses, with greater suitability than warfarin.

Study Methodology

• The study involved eight adult horses to whom the researchers applied single oral and intravenous administrations of 0.75 mg/kg racemic phenprocoumon.
• The plasma concentration of phenprocoumon showed a biphasic decline in time after intravenous administration, which was calculated using a two-compartment open model.

Key Findings

• The average plasma half-life was found to be 22 hours, the apparent volume of distribution was 0.61 l/kg, and the Cltot stood at 25.2 ml/kg/h.
• Following oral administration of phenprocoumon, its systemic bioavailability was 97.6%, with Tmax falling within the 4-12 hours range.

Effects on Coagulation System

• The study measured phenprocoumon’s effects on the coagulation system by observing the activity of Factor X, Quick’s one stage prothrombin time, and the PTT (Partial Thromboplastin Time).
• Factor X displayed the most pronounced effect from phenprocoumon administration. Over 7-9 days, a reduction to 11-33% of the content of Factor X was noted.

Comparison with Warfarin

• The Quick’s one stage prothrombin time was reduced over 4-8 days, with the lowest values standing at 22-55%.
• The PTT presented a minor reaction to a single administration of 0.75 mg/kg phenprocoumon.
• No notable disparities in the effect on coagulation between the two approaches (intravenous and oral) were identified.
• Phenprocoumon exhibited a longer half-life period and created a significantly extended hypothrombogenic reaction as compared to warfarin. Therefore, it appears to be a comparatively more fitting choice for extended anticoagulation therapy in horses.