Sublingual administration of detomidine in horses: sedative effect, analgesia and detection time.

The research assessed the sedative and analgesic influence of a sublingual (under the tongue) administration of detomidine gel in horses. According to the study, the medication’s effects and its presence in blood and urine were monitored for 8 days after administration. The findings reveal that the horses tested negative for the drug in their blood and urine 48 and 60 hours after administration, respectively, suggesting a safe withdrawal time of 72 hours after administering the drug.

Study Design and Implementation

• The research involved 10 healthy Dutch Warmblood mares with an average age and weight of 7 ± 4 years and 580 ± 69 kg, respectively.
• A single dose of 40 μg/kg bodyweight (BW) of oromucosal detomidine gel was administered sublingually to each horse.
• Observations were tracked and blood and urine samples collected before and for 8 days following the medication’s administration.

Methodology and Assessments

• The samples were examined both at an FEI Reference Laboratory for qualitative review and a research laboratory for quantitative analysis.
• Sedation was determined by measuring the height of the horse’s head and scores of reaction to auditory and mixed auditory/sensory stimuli.
• The Mechanical nociceptive thresholds (MNTs) were assessed using pressure algometry to evaluate analgesia.
• Additional parameters including heart rate and ataxia (loss of control of body movements) were also evaluated.

Study Findings

• The horses were considered negative for detomidine in their blood samples by 48 hours after the medication was administered, and by 60 hours in their urine samples.
• Based on these results, the study suggests that a safe withdrawal time for detomidine oromucosal gel may be 72 hours following a single sublingual administration of 40 μg/kgBW.
• Notably, decreases in heart rate and head height peaked at 40 and 60 minutes post-administration, respectively.
• Maximum decrease in response to stimuli was observed at 120 minutes after the medication was given, and ataxia peaked 60 minutes after administration.
• At 40 and 80 minutes after medicating, the analgesic effect of the medication was seen to significantly increased when compared to baseline measures. All parameters, except the MNTs of two locations – which were decreased – returned to baseline values within 24 hours post-administration.