Detomidine is an

imidazole Imidazole (ImH) is an organic compound with the formula C3N2H4. It is a white or colourless solid that is soluble in water, producing a mildly alkaline solution. In chemistry, it is an aromatic heterocycle, classified as a diazole, and has non-a ...

derivative and α₂-adrenergic agonist, used as a large animal sedative, primarily used in

horse The horse (''Equus ferus caballus'') is a domesticated, one-toed, hoofed mammal. It belongs to the taxonomic family Equidae and is one of two extant subspecies of ''Equus ferus''. The horse has evolved over the past 45 to 55 million yea ...

s. It is usually available as the

salt Salt is a mineral composed primarily of sodium chloride (NaCl), a chemical compound belonging to the larger class of salts; salt in the form of a natural crystalline mineral is known as rock salt or halite. Salt is present in vast quant ...

detomidine

hydrochloride In chemistry, a hydrochloride is an acid salt resulting, or regarded as resulting, from the reaction of hydrochloric acid with an organic base (e.g. an amine). An alternative name is chlorhydrate, which comes from French. An archaic alternative n ...

. It is a

prescription medication A prescription drug (also prescription medication or prescription medicine) is a pharmaceutical drug that legally requires a medical prescription to be dispensed. In contrast, over-the-counter drugs can be obtained without a prescription. The r ...

available to veterinarians sold under various trade names. Currently, detomidine is licensed for use only in horses in the US but it is also licensed for use in cattle in Europe and Australasia.

Properties

Detomidine is a sedative with analgesic properties. α2-adrenergic agonists produce dose-dependent sedative and analgesic effects, mediated by activation of α2

catecholamine A catecholamine (; abbreviated CA) is a monoamine neurotransmitter, an organic compound that has a catechol (benzene with two hydroxyl side groups next to each other) and a side-chain amine. Catechol can be either a free molecule or a su ...

receptors, thus inducing a negative feedback response, reducing production of excitatory neurotransmitters. Due to inhibition of the sympathetic nervous system, detomidine also has cardiac and respiratory effects and an antidiuretic action.

Effects

A profound lethargy and characteristic lowering of the head with reduced sensitivity to environmental stimuli (sound, pain, etc.) are seen with detomidine. A short period of reduced coordination is characteristically followed by immobility and a firm stance with front legs spread. Following administration there is an initial increase in blood pressure, followed by bradycardia and second degree

atrioventricular block Atrioventricular block (AV block) is a type of heart block that occurs when the electrical signal traveling from the atria, or the upper chambers of the heart, to ventricles, or the lower chambers of the heart, is impaired. Normally, the sinoatr ...

(this is not

pathologic ''Pathologic'' ( rus, Мор. Утопия, Mor. Utopiya, ˈmor ʊˈtopʲɪjə, , More. Utopia – a pun on Thomas More's ''Utopia'' and the Russian word for "plague") is a 2005 role-playing and survival game developed by Russian studio Ice-Pic ...

in horses). The horse commonly

sweat Perspiration, also known as sweating, is the production of fluids secreted by the sweat glands in the skin of mammals. Two types of sweat glands can be found in humans: eccrine glands and apocrine glands. The eccrine sweat glands are distrib ...

s to excess, especially on the flanks and neck. Other side effects reported include pilo erection (hair standing erect),

ataxia Ataxia is a neurological sign consisting of lack of voluntary coordination of muscle movements that can include gait abnormality, speech changes, and abnormalities in eye movements. Ataxia is a clinical manifestation indicating dysfunction of ...

, salivation, slight muscle tremors, and (rarely) penile prolapse.

Uses

Sedation and anaesthetic premedication in horses and other large animals, commonly combined with

butorphanol Butorphanol is a morphinan-type synthetic agonist–antagonist opioid analgesic developed by Bristol-Myers. Butorphanol is most closely structurally related to levorphanol. Butorphanol is available as the tartrate salt in injectable, tablet, and ...

for increased analgesia and depth of sedation. In conjunction with

ketamine Ketamine is a dissociative anesthetic used medically for induction and maintenance of anesthesia. It is also used as a recreational drug. It is one of the safest anesthetics, as, in contrast with opiates, ether, and propofol, it suppresses ...

it may also be used for intravenous

anaesthesia Anesthesia is a state of controlled, temporary loss of sensation or awareness that is induced for medical or veterinary purposes. It may include some or all of analgesia (relief from or prevention of pain), paralysis (muscle relaxation), a ...

of short duration. The drug is normally administered by the intravenous route, and is fastest and most efficient when given intravenously . However, in recalcitrant animals, detomidine may be administered by the

intramuscular Intramuscular injection, often abbreviated IM, is the injection of a substance into a muscle. In medicine, it is one of several methods for parenteral administration of medications. Intramuscular injection may be preferred because muscles have ...

or sublingual routes. The dose range advised by the manufacturers is 20–40 µg/kg intravenous for moderate sedation, but this dose may need to be higher if given intramuscularly. When given intravenously, detomidine usually takes effect in 2–5 minutes, and recovery is full within 30–60 minutes. However, this is highly dependent upon the dosage, environment, and the individual animal; some horses are highly resistant to sedation.

Cautions

As detomidine is an

arrhythmogenic Arrhythmias, also known as cardiac arrhythmias, heart arrhythmias, or dysrhythmias, are irregularities in the Cardiac cycle, heartbeat, including when it is too fast or too slow. A resting heart rate that is too fast – above 100 beats per mi ...

agent, extreme care should be exercised in horses with cardiac disease, and in the concurrent administration of other arrhythmogenics. The concurrent use of potentiated sulfonamide

antibiotics An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention o ...

is considered particularly dangerous. Anesthetic recoveries in horses that have received ketamine following a detomidine premedication are often violent with the horse having multiple failures to stand resulting in trauma to itself.

Xylazine Xylazine is a pharmaceutical drug used for sedation, anesthesia, muscle relaxation, and analgesia in animals such as horses, cattle, and other non-human mammals. Veterinarians also use xylazine as an emetic, especially in cats. It is an anal ...

is a superior premedication with ketamine resulting in safer recoveries.

References

External links