Comparative pharmacokinetics of two intravenous administration regimens of tiludronate in healthy adult horses and effects on the bone resorption marker CTX-1.

The study compares the availability and effects of Tiludronate, a drug given to healthy horses, when administered in two different dosing methods. One group gets a regular dosage over 10 days, and the other gets a single dose. Both methods produced similar effects on the horse’s health.

Objective of the Study

The goal of the study was to compare:

• The bioavailability,
• The pharmacological effects of tiludronate,
• The influence on the bone resorption marker CTX-1,

in two groups of healthy horses, each treated with a different regimen of intravenous tiludronate administration.

Research Design

A total of 12 healthy adult horses were divided into two groups, each treated with tiludronate differently:

• Group 1 (6 horses) was administered a daily dosage of 0.1 mg/kg body weight of tiludronate through intravenous bolus for ten consecutive days,
• Group 2 (6 horses) was treated with a single constant rate infusion of a total dose of 1 mg/kg body weight.

Measurements and Results

The researchers measured the concentration of tiludronate and CTX-1 (a bone resorption marker) in the plasma and urine of the horses. They found:

• There was no statistically significant difference in the area under the curve (AUC) and clearance (Cl) between the two groups, which means both treatments produced a similar exposure of tiludronate in the bloodstream.
• The bioavailability in Group 2 was 103% of Group 1, a result that was not considered statistically meaningful.
• Urine tiludronate excretion could not be compared because the assay was not sensitive enough in urine.
• There were no differences in plasma and urine CTX-1 levels between the two groups throughout the study, but there were more variations between individuals in Group 1 than in Group 2.
• A significant decrease in plasma CTX-1 levels was observed after the first treatment application in Group 1, but not in the urine. In Group 2, however, a significant drop in plasma and urine CTX-1 levels was seen after administration.

Conclusion

Overall, both methods of administering tiludronate resulted in similar plasma exposure and pharmacological effects. The findings suggest both dosing regimens are effective for treating adult healthy horses with tiludronate.