Hubbry Logo
DetomidineDetomidineMain
Open search
Detomidine
Community hub
Detomidine
logo
8 pages, 0 posts
0 subscribers
Be the first to start a discussion here.
Be the first to start a discussion here.
Contribute something
Detomidine
Detomidine
from Wikipedia

Detomidine
Clinical data
AHFS/Drugs.comInternational Drug Names
ATCvet code
Legal status
Legal status
  • Veterinary use only
Pharmacokinetic data
Elimination half-life30 min
Identifiers
  • 4-[(2,3-dimethylphenyl)methyl]-3H-imidazole
CAS Number
PubChem CID
ChemSpider
UNII
KEGG
ChEMBL
CompTox Dashboard (EPA)
Chemical and physical data
FormulaC12H14N2
Molar mass186.258 g·mol−1
3D model (JSmol)
  • Cc2cccc(Cc1cnc[nH]1)c2C
  • InChI=1S/C12H14N2/c1-9-4-3-5-11(10(9)2)6-12-7-13-8-14-12/h3-5,7-8H,6H2,1-2H3,(H,13,14) checkY
  • Key:RHDJRPPFURBGLQ-UHFFFAOYSA-N checkY
 ☒NcheckY (what is this?)  (verify)

Detomidine is an imidazole derivative and α2-adrenergic receptor agonist,[1] used as a large animal sedative, primarily used in horses. It is usually available as the salt detomidine hydrochloride. It is a prescription medication available to veterinarians sold under various trade names.

Use

[edit]

Currently, detomidine is licensed for use only in non-meat horses in the United States, but it is also licensed for use in cattle in Europe and Australia.[2][3] Detomidine's withholding period is 12–72 hours for dairy cattle and 2–3 days for meat cattle.[3]

Properties

[edit]

Detomidine is a sedative with analgesic properties.[4] α2-adrenergic receptor agonists produce dose-dependent sedative and analgesic effects, mediated by activation of α2 catecholamine 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.[5]

Pharmacology

[edit]

Detomidine is an α2-adrenergic receptor agonist that binds at a ratio of 260:1 with imidazoline receptor activity.[3]

Veterinary use

[edit]

Detomidine is administered intramuscularly. Oral transmucosal has been investigated and is used in some countries although it has poor bioavailability of around 20–25%.[3] Intravaginal administration in the horse and alpaca has induced sedation.[3]

Detomidine administration in sheep activates pulmonary macrophages that damage the endothelium of capillaries and alveolar type I cells. This in turns causes alveolar haemorrhage and oedema causing hypoxaemia.[3][6][7]

References

[edit]
[edit]
Revisions and contributorsEdit on WikipediaRead on Wikipedia
from Grokipedia
Detomidine is a synthetic α₂-adrenergic used as a and in , primarily for horses and yearlings to facilitate minor surgical and diagnostic procedures. Administered as detomidine , it is available in injectable solutions (typically 10 mg/mL) for intravenous or intramuscular use, with dosages ranging from 20 to 40 μg/kg body weight to achieve dose-dependent lasting 30 minutes to 2 hours and analgesia for 30 to 75 minutes. The drug produces rapid effects by stimulating central and peripheral α₂-adrenoceptors, leading to reduced sensitivity to external stimuli, muscle relaxation, and altered cardiovascular and respiratory functions. In , detomidine initially causes and due to peripheral α₂-receptor , followed by a centrally mediated decrease in sympathetic outflow that normalizes while slowing and respiration. It also inhibits insulin release, potentially elevating blood glucose levels, and depresses gastrointestinal motility by reducing activity, which may contribute to side effects like , sweating, piloerection, and increased salivation. Common adverse effects include occasional arrhythmias, such as partial atrioventricular or sinoatrial blocks, and profuse approximately 45 to 60 minutes post-administration; these are generally transient but require monitoring, especially in horses with pre-existing cardiac conditions. Approved by the U.S. Food and Drug Administration (FDA) under NADA #140-862 in the early 1990s, detomidine hydrochloride has been a standard veterinary agent since its original approval, with generic versions becoming available in 2020 to provide bioequivalent alternatives to branded products like Dormosedan. While primarily indicated for equines, it has been studied for use in other species such as cattle, alpacas, and foals, where it demonstrates similar sedative and analgesic properties at adjusted doses, though efficacy can vary. Safety precautions emphasize avoiding human exposure, as accidental self-injection can cause severe sedation and cardiovascular effects, necessitating immediate medical attention.

Introduction and History

Chemical Structure and Properties

Detomidine is an imidazole derivative with the chemical formula C₁₂H₁₄N₂ and a molecular weight of 186.25 g/mol for the free base form. The commonly used hydrochloride salt has the formula C₁₂H₁₅ClN₂ and a molecular weight of 222.71 g/mol. Its structure consists of an imidazole ring substituted at the 4-position with a (2,3-dimethylphenyl)methyl group, which contributes to its selectivity for alpha-2 adrenergic receptors. Physically, detomidine hydrochloride appears as a white crystalline powder that is highly soluble in , with solubility exceeding 27 mg/mL. It has a pKa of approximately 7.15 for the strongest basic site, reflecting the behavior of the nitrogen. The compound is stable under normal storage conditions, such as controlled (15–30°C) away from , with no significant reactivity reported. As a selective alpha-2 , detomidine exhibits and effects primarily through its high affinity for alpha-2 receptors, with an alpha-2 to alpha-1 binding selectivity ratio of 260:1. It also demonstrates minor activity at , which may contribute to its overall pharmacological profile.

Development and Approvals

Detomidine was developed by Orion Pharma in during the 1970s as a potential antihypertensive agent for use, but its pronounced side effects prompted a shift toward veterinary applications. Key milestones in its development include the first marketing authorization in in 1983, where it was approved as a and for horses and under the brand name Domosedan. This marked the beginning of its commercial availability in , with subsequent approvals expanding its use for sedation and restraint in equine and bovine species across the during the 1980s and 1990s. In the United States, the FDA granted approval for the injectable form of detomidine hydrochloride (Dormosedan) under 140-862 on December 6, 1989, specifically for and analgesia in mature . The first generic version, detomidine hydrochloride injectable solution, received FDA approval on April 27, 2020, providing a bioequivalent alternative for equine use. Additionally, an oral transmucosal gel formulation (Dormosedan Gel) was approved by the FDA under 141-306 on March 22, 2010, offering a non-injectable option for sedating during minor procedures. Further evolution in the included refinements to transmucosal delivery systems, enhancing ease of administration in veterinary practice, though detomidine has never received regulatory approval for use owing to its profile.

Pharmacology

Mechanism of Action

Detomidine acts primarily as a highly selective at alpha-2 adrenergic receptors located both presynaptically and postsynaptically in the (CNS). It exhibits a selectivity of :1 for alpha-2 over alpha-1 adrenergic receptors, enabling targeted activation with minimal interference from alpha-1 mediated effects. This binding inhibits the release of norepinephrine from presynaptic alpha-2 autoreceptors, particularly in the , thereby reducing sympathetic outflow from the CNS. The activation of central alpha-2 receptors by detomidine leads to dose-dependent , analgesia, and muscle relaxation through hyperpolarization of neurons and suppression of excitatory neurotransmission. Peripherally, stimulation of postsynaptic alpha-2 receptors on vascular causes , which contributes to initial , while activation in the kidneys promotes by inhibiting (ADH) release. In addition to its primary alpha-2 adrenergic activity, detomidine shows minor binding affinity to , particularly I-receptors in tissues like the liver, though this interaction is of lesser pharmacological significance. It lacks significant activity at receptors, as its sedative effects are not antagonized by . The is largely consistent across mammalian , with detomidine demonstrating comparable potency in and , where equivalent effects are achieved at similar doses despite minor pharmacokinetic differences.

Pharmacokinetics

Detomidine exhibits rapid absorption following intramuscular administration in horses, with peak plasma concentrations occurring approximately 30 minutes after dosing and an absorption of about 0.15 hours. Intravenous administration results in immediate onset of systemic exposure, while sublingual oromucosal administration yields a mean of 22% in horses, lower than the 38% observed with intramuscular dosing. In , absorption is even faster, with an absorption of 0.08 hours and peak concentrations at 15-20 minutes post-intramuscular injection. The drug is highly lipophilic, facilitating extensive penetration into the , where brain concentrations can reach three times those in plasma. In , the volume of distribution ranges from 0.69 to 1.89 L/kg, reflecting broad tissue distribution, and protein binding is approximately 85%. Similar distribution characteristics are noted in , with a volume of distribution around 0.73 L/kg following intravenous dosing. Detomidine undergoes hepatic in , primarily forming inactive metabolites such as 3-hydroxy-detomidine and detomidine 3-carboxylic acid, with no active metabolites identified. occurs rapidly, contributing to the drug's short duration of action, and is nearly complete, as unchanged detomidine constitutes less than 1.5% of urinary excretion products. Elimination half-life in horses is approximately 30 minutes following intravenous administration and 1 hour after intramuscular dosing, with total clearance around 12 ml/min/kg. is predominantly renal, with 60-70% of metabolites eliminated in , and a smaller portion via ; renal clearance accounts for less than 1% of total clearance, indicating minimal unchanged . In ruminants like , clearance is slower, with half-lives of 1.3 hours intravenously and up to 2.6 hours intramuscularly, and no accumulation occurs with repeated dosing in either species.

Veterinary Uses

In Horses

Detomidine is widely used in equine as a and agent, particularly for and restraint during minor surgical, diagnostic, or grooming procedures. It also provides effective analgesia for managing and wounds, facilitating handling and treatment in these scenarios. Often, detomidine is combined with opioids such as to potentiate its and effects, allowing for smoother procedural interventions in . The drug induces moderate to deep lasting 30 to , offering reliable restraint for clinical applications. This is reversible using alpha-2 antagonists like , enabling rapid recovery when needed. Its sedative mechanism involves activation of alpha-2 adrenergic receptors in the , as detailed in the section. In common protocols, detomidine is administered alone or as part of cocktails to support various equine procedures. Recent studies, including those up to 2020 with ongoing relevance, have demonstrated the efficacy of oromucosal gel formulations in alleviating acute anxiety and fear associated with noise phobias, such as , providing a non-invasive option for behavioral management. Compared to alternatives like , detomidine offers a longer duration of and reduced at lower doses, making it preferable for prolonged restraint with minimal locomotor impairment.

In Other Animals

Detomidine is licensed for sedation and mild analgesia in in to facilitate procedures such as physical examinations, minor surgeries, and dehorning, administered at doses of 0.01–0.04 mg/kg intramuscularly or intravenously, with established withdrawal times of 12 hours for and 2 days for meat. Similar approvals exist in for restraint during veterinary interventions. However, it lacks FDA approval for use in food-producing animals due to residue concerns. Detomidine has been evaluated for in alpacas, producing moderate effects when administered intravenously or as an intravaginal . In sheep, detomidine is used off-label for short-term , but its application is limited by risks of arterial and , particularly at higher doses. For dogs and cats, it provides short-term and analgesia in clinical settings, though is generally preferred for its superior potency and reversibility. In , detomidine is incorporated into dart-delivered combinations, such as with , for safe capture and immobilization of species like nonhuman primates, minimizing stress during handling. Experimental studies in pigs, including a study, indicate detomidine's potential for restraint and anesthesia when combined with agents like tiletamine-zolazepam or , offering effective sedation but with elevated cardiovascular risks including and . Overall, detomidine's use in non-equine species remains less prevalent than in horses owing to inconsistent efficacy across taxa and species-specific safety profiles.

Administration and Dosage

Routes of Administration

Detomidine is primarily administered via parenteral and oral transmucosal routes in veterinary practice, with formulations designed for specific delivery methods to achieve and analgesia in animals such as . The injectable form, detomidine solution at a concentration of 10 mg/mL, is commonly given intravenously (IV) for rapid or intramuscularly () for standard procedures. This route ensures high and quick absorption, though pharmacokinetic variations exist depending on the method. is not recommended due to potential localized inflammatory responses and tissue irritation from accidental injection. Oral transmucosal administration involves a formulation of detomidine , applied sublingually (under the ) for non-invasive delivery, particularly in where it provides suitable for minor procedures. This route yields a of approximately 22% in , with absorption occurring through the . Intravaginal administration of the detomidine gel has been explored in settings, such as in alpacas, where it produced moderate without adverse effects at tested doses, though it remains investigational and not approved for routine use. No topical or inhaled forms of detomidine are currently approved for veterinary application. Available forms include the injectable hydrochloride salt in multidose vials of 5 mL or 20 mL, and the transmucosal gel in pre-filled syringes for precise dosing. All administrations require veterinary supervision to monitor effects and manage potential reversal with agents such as , typically given IV or IM.

Dosing Guidelines

Detomidine dosing in varies by species, intended effect ( versus analgesia), and , with guidelines emphasizing dose titration based on individual response and clinical status. In , the standard dose for is 0.02–0.04 mg/kg administered intravenously (IV) or intramuscularly (), providing 30–120 minutes of effect depending on the dose; doses of 0.02–0.04 mg/kg IV or are used for and/or analgesia, yielding durations of 30–75 minutes. For sublingual administration using the oromucosal gel formulation, a dose of 0.04 mg/kg is recommended, with onset in approximately 40 minutes and lasting 90–180 minutes. These recommendations are derived from product labeling and clinical studies, with higher doses (up to 0.08 mg/kg) reserved for prolonged but increasing the risk of cardiovascular effects. In cattle, detomidine is typically dosed at 0.02–0.04 mg/kg IM or IV for moderate sedation and minor procedures, with durations of 0.5–1 hour; doses may be adjusted upward to 0.08 mg/kg for extended effects up to 3 hours, always accounting for body weight to avoid over-sedation in larger animals. Dosing should be conservative in hypovolemic or shocked cattle, reducing the initial amount by 25–50% to mitigate exacerbation of hypotension. For other species, detomidine use is often off-label. In dogs, IM doses of 0.02–0.04 mg/kg provide sedation for clinical examinations, though monitoring is essential due to limited approval and potential for respiratory changes. In sheep, an IM dose of 0.02–0.05 mg/kg induces sedation, but close observation of respiration is required, as rates may decrease significantly post-administration. Dose adjustments are critical in certain conditions; in hypovolemic animals across species, reduce the dose by 25–50% to prevent cardiovascular compromise. For , a common , co-administration of anticholinergics such as glycopyrrolate (0.005–0.01 mg/kg IM) is recommended in and to maintain stability. Reversal of detomidine effects can be achieved with at 0.1–0.15 mg/kg IV or IM, with faster and more complete antagonism in at higher ends of this range for deeper . Ongoing monitoring during detomidine use includes serial assessments of (expect decreases to 20–40 bpm in ) and (potential reductions to 8–12 breaths/min), performed every 5– until recovery. These parameters help ensure , particularly in scenarios.

Safety and Adverse Effects

Effects in Animals

Detomidine administration in animals commonly induces cardiovascular effects, including , transient , and arrhythmias such as first- and second-degree atrioventricular (AV) block. These changes typically occur shortly after injection and may require intervention with atropine sulfate at 0.02 mg/kg intravenously to prevent or treat and . In , is particularly pronounced, often leading to heart rates below 40 beats per minute, while may initially occur before develops. Respiratory effects are generally mild, manifesting as slight depression in , but more severe complications can arise in ruminants. In sheep, detomidine causes marked due to endothelial damage in pulmonary capillaries and alveolar hemorrhage, potentially leading to . These ruminant-specific pulmonary risks highlight the need for careful monitoring during sedation. Other adverse effects include , , piloerection, muscle tremors, sweating, and inhibition of urination. Penile prolapse occurs rarely in stallions and geldings, typically resolving without intervention. In , additional reactions such as ruminal atony, tympanism, and may be observed. These effects are dose-dependent and usually transient at standard doses. Overdose with detomidine results in profound , respiratory and , , cardiac arrhythmias, and potential collapse. Recovery can be delayed, but these effects are reversible with alpha-2 adrenergic antagonists such as , administered at doses approximately 3-4 times the detomidine amount. Studies through 2025 indicate no long-term adverse effects from detomidine at standard therapeutic doses in horses, , and sheep, with effects primarily limited to the period and resolving without sequelae.

Risks to

Detomidine is not approved for use and poses significant risks through accidental exposure, primarily to veterinary personnel during handling. Common exposure routes include dermal absorption via skin contact, especially on broken or irritated skin; accidental injection, such as self-injection or needle sticks; of vapors; and oral from contaminated hands or contact after administration to animals. Accidental exposure to detomidine can cause , manifesting as , drowsiness, , , dry mouth, and dilated pupils. In severe cases, particularly with higher doses, effects may progress to respiratory depression or , though documented human cases have not typically required . Unlike opioids, detomidine carries no potential for but induces profound CNS depression due to its alpha-2 activity, similar to the human-approved . Management of human exposure focuses on supportive care, including immediate : washing affected skin with soap and water, flushing eyes with water for at least 15 minutes, and rinsing the mouth for without inducing vomiting. For oral , activated charcoal may be administered to reduce absorption if presentation is prompt. , an alpha-2 antagonist used in , can reverse effects but is not FDA-approved for humans and should only be considered under medical supervision. Affected individuals should seek immediate medical attention, avoid driving or operating machinery, and contact poison control centers for guidance. Veterinary product labels, including those approved by the FDA, carry prominent warnings emphasizing the use of impermeable gloves during handling and for up to two hours afterward when managing the animal's to prevent absorption. Direct contact with skin, eyes, or mucous membranes must be avoided, and individuals with pre-existing cardiovascular conditions are advised to exercise extra caution. Rare reports of intentional exist, but diversion is managed through controlled veterinary distribution. Emerging 2025 reviews note limited illicit of drugs with detomidine, unlike more common adulterants such as or . Toxicological data indicate low in , with an oral LD50 of 60 mg/kg in rats. Human case studies are limited to four reported incidents, primarily accidental during veterinary procedures, demonstrating dose-dependent that resolves with supportive care and observation, typically without long-term sequelae.

Regulatory Aspects

Licensing and Availability

In the , detomidine is FDA-approved exclusively for use in non-food-producing as a and , marketed under the trade name Dormosedan in both injectable solution and oral gel formulations by . The first generic version, Detomidine Injectable Solution, was approved in 2020 by Bimeda as a bioequivalent alternative, with additional generics available since then. It is classified as a prescription-only (POM-V equivalent), requiring administration by or under the direction of a licensed , and is not available over-the-counter. In Europe, detomidine is authorized by the European Medicines Agency (EMA) and national regulatory bodies for use in both horses and cattle, with approvals covering sedation and analgesia. Common trade names include Domidine (Dechra) and Domosedan, available as injectable solutions, and it holds prescription-only status across member states. In other regions, detomidine is approved in and for use in (and under similar veterinary oversight), marketed as Sedator Injection with APVMA and ACVM registrations. In , it is authorized for equines under trade names like Dormosedan () and Domidine (Dechra), but approvals are more limited compared to broader food animal uses elsewhere, remaining prescription-only. Globally, detomidine is distributed under trade names such as and various generics, with no over-the-counter availability due to its status as a . As of 2025, its regulatory status remains unchanged, though authorities continue monitoring for potential illicit diversion similar to other alpha-2 agonists, and it is not designated as a under international conventions.

Withdrawal Periods

In the , where are not considered food-producing animals, no mandatory withdrawal period is required for detomidine following its use in . However, for performance in contexts, a 2-day (48-hour) withdrawal period is recommended to avoid detection in plasma or urine samples, based on pharmacokinetic studies and regulatory guidelines from bodies like the Racing Medication and Testing Consortium (RMTC). For in the and , official product summaries specify a withholding period of 12 hours and a withdrawal period of 2 days after intramuscular administration of detomidine at approved doses (0.01–0.04 mg/kg). Some veterinary recommendations, particularly for extra-label or higher doses, extend the withholding to 72 hours and withdrawal to 3 days to account for residue depletion. In other species such as sheep and goats, detomidine use is off-label in most jurisdictions, with recommended meat withdrawal periods of 3 days and milk withholding of 72 hours following intramuscular administration, per guidelines for extra-label use; official label data are limited due to lack of approval for lactating animals. Withdrawal periods for detomidine are determined based on its , including an elimination that influences residue clearance, with longer intervals required for oral or transmucosal routes compared to intravenous or intramuscular administration. As of 2025, these guidelines remain unchanged across major regulatory bodies, supported by ongoing residue monitoring programs to ensure . Compliance with withdrawal periods mandates detailed veterinary records of administration, including dose, route, and date, to prevent residues in products; violations can result in regulatory fines, product seizures, or legal penalties under frameworks like the U.S. Federal , , and Cosmetic Act or EU veterinary medicinal product regulations.

References

Add your contribution
Related Hubs
Contribute something
User Avatar
No comments yet.