Pharmacokinetics and effects of cetirizine in horses with insect bite hypersensitivity.

This research examines the impact of the antihistamine cetirizine on horses suffering from insect bite hypersensitivity (IBH). However, the study found that cetirizine did not significantly reduce dermatitis symptoms in these horses, while strategies such as using protection blankets and stabling showed more effectiveness.

Objective and Methodology

• In this study, the researchers sought to analyze the efficacy of cetirizine, an antihistamine, in treating horses with insect bite hypersensitivity (IBH).
• Recognizing that horses with IBH face challenges in avoiding allergens, the study aimed to offer a potential pharmaceutical treatment.
• The research deployed a randomised, placebo-controlled, double-blinded field study design. The study administered cetirizine orally at a dosage of 0.4 mg/kg twice daily for three weeks.
• Aside from assessing the impact of cetirizine, the study evaluated the effects of other preventive measures such as protection blankets and stabling.

Results

• The study observed a maximum and trough plasma concentration of cetirizine at 135 ng/mL and 18 ng/mL, respectively.
• Regarding dermatitis reduction, the study found no significant difference between the cetirizine treatment group and the placebo group, indicating that the antihistamine was not effective at the tested dosage.

Other Findings and Conclusion

• Interestingly, where the cetirizine treatment might have failed, using protection blankets and stabling registered a favorable influence on the horses’ dermatitis.
• The study concluded that these non-pharmaceutical methods might serve as more effective options to prevent dermatitis associated with IBH, as opposed to cetirizine treatment at the dose rate tested.