DETOMIDINE HCL

Chemistry - An imidazoline derivative alpha2-adrenergic agonist, detomidine HCl occurs as awhite crystalline substance that is soluble in water.

Storage, Stability, Compatibility

Detomidine HCl for injection should be stored at room temperature (15-30°C) and be protected from light.

Pharmacology - DETOMIDINE HCL

Detomidine, like xylazine is an alpha2-adrenergic agonist that produces a dose-dependent sedative and analgesic effect, but also has cardiac and respiratory effects. For more information refer to the xylazine monograph or the adverse effects section below.
Uses, Indications - At the present time detomidine is only approved for use as a sedative analgesicin horses, but it also has been used clinically in other species.

Pharmacokinetics - DETOMIDINE HCL

Detomidine is well absorbed after oral administration, but is used only parenterally at the present time. The drug is apparently rapidly distributed into tissues, including the brain after parenteral administration and is extensively metabolized and then excreted primarily into the urine.

Contraindications, Precautions, Reproductive Safety

Detomidine is contraindicated in horseswith preexisting AV or SA heart block, severe coronary insufficiency, cerebrovascular disease, respiratory disease or chronic renal failure. It should be used with caution in animals with endotoxicor traumatic shock or approaching shock, and advanced hepatic or renal disease. Horses who arestressed due to temperature extremes, fatigue, or high altitude should also receive the drug withcaution.
Although animals may appear to be deeply sedated, some may respond to external stimuli; useappropriate caution. The manufacturer recommends allowing the horse to stand quietly for 5minutes prior to injection and for 10-15 minutes after injection to improve the effect of the drug.
After administering detomidine, protect the animal from temperature extremes.

Adverse Effects, Warnings

Detomidine can cause an initial rise in blood pressure which is thenfollowed by bradycardia and heart block. Atropine at 0.02 mg/kg IV has been successfully used toprevent or correct the bradycardia that may be seen when the detomidine is used at labeled dosages.
Also, piloerection, sweating, salivation, slight muscle tremors, and penile prolapse may all be notedafter injection.

Overdosage, Acute Toxicity

The manufacturer states that detomidine is tolerated by horses atdoses 5 times (0.2 mg/kg) the high dose level (0.04 mg/kg). Doses of 0.4 mg/kg given daily for 3consecutive days produced microscopic foci of myocardial necrosis in 1 of 8 horses tested. Dosesof 10-40 times those recommended can cause severe respiratory and cardiovascular changes whichcan become irreversible and cause death. Yohimbine theoretically could be used to reverse some orall of the effects of the drug, but not enough clinical experience has been reported to make anyrecommendations for its use at this time.

Drug Interactions

The manufacturer warns against using this agent with intravenous potentiated sulfonamides (e.g., trimethoprim/sulfa) as fatal dysrhythmias may occur, and to use with extreme caution in combination with other sedative or analgesic drugs. Because this is a relatively new drug, more interactions may be forthcoming; refer to the xylazine monograph for more information on interactions with alpha2-adrenergic agonists.