Tiletamine

2-(ethylamino)-2-thiophen-2-ylcyclohexan-1-one

Overview

Tiletamine belongs to Dissociatives / Arylcyclohexylamines.

Key safety note: Tiletamine is a potent veterinary dissociative anaesthetic with a narrow, species-dependent safety margin and no role in human medicine.[2]
Effects
Subjective effects vary. What a substance feels like depends on dose, individual physiology, mindset, and setting. The points below describe commonly reported effects, not guaranteed, uniform, or desirable outcomes.
  • Rapid dissociative anaesthesia: analgesia and catalepsy with open eyes, detachment from the environment.
  • Muscle rigidity and involuntary movements, with excessive salivation.
  • A prolonged, sometimes rough or convulsive recovery with hypersensitivity to stimulation (the reason zolazepam is co-administered).
Dosing & duration
Harm-reduction note: These are commonly cited reference ranges, not a recommendation or a “safe” dose. Potency, purity, body chemistry, tolerance, and drug combinations vary widely. Start low, go slow, wait for full effects before redosing, and never assume an unknown product matches these figures. Missing data is not evidence of safety.

Injectable (IM/IV) veterinary anaesthetic, given by a veterinarian as the zolazepam combination (Telazol/Zoletil). There is no established or safe human dose. Figures are veterinary context only.. Tiletamine is dosed by body weight and titrated by a veterinarian as part of the zolazepam combination, with monitoring of airway, breathing and circulation. It has no validated human use. Diverted veterinary product is dangerous: the concentration and dose are formulated for animals and the dissociative effect is intense and unpredictable.

Dose ranges

Duration

onset

Rapid (IM/IV)

total

≈30 min surgical anaesthesia (Telazol combination)

after effects

Prolonged, sometimes rough recovery

Chemical & Physical Properties
FormulaC12H17NOS
Molar mass223.34 g/mol
StateSolid (usually the hydrochloride salt [Telazol/Zoletil], an odourless white crystalline powder, no experimental melting point reported for the free base)
Melting point186–188 °C (decomposes): hydrochloride salt (CAS 14176-50-2)
Boiling pointNot reported
DensityNot reported
Vapor pressureNot reported
pKaNot reported
LogP2 (predicted, XLogP3, free base)
SolubilityHydrochloride salt is water-soluble (Telazol is reconstituted in water)
Refractive indexNot reported
Identifiers & Synonyms
CAS14176-49-9
CAS (enantiomer)
PubChem CID26533
InChIKeyQAXBVGVYDCAVLV-UHFFFAOYSA-N
InChIInChI=1S/C12H17NOS/c1-2-13-12(11-7-5-9-15-11)8-4-3-6-10(12)14/h5,7,9,13H,2-4,6,8H2,1H3
SMILESCCNC1(CCCCC1=O)C2=CC=CS2

Synonyms

  • Telazol
  • Zoletil
  • CI-634
Pharmacodynamics & Biochemistry

Tiletamine is a dissociative anaesthetic of the arylcyclohexylamine class and a close relative of ketamine. It replaces ketamine's chlorophenyl group with a thiophene ring and its N-methyl with an N-ethyl group. Like the rest of the class it is an open-channel (non-competitive) antagonist at the NMDA glutamate receptor: it binds inside the ion channel at the phencyclidine (PCP) site and blocks it use-dependently, dissociating the cortex from sensory input to produce profound analgesia and catalepsy with the eyes open rather than classic sleep. A tiletamine-specific binding study found it displaces [³H]TCP from the NMDA-coupled PCP recognition site with an IC50 of about 79 nM (rat brain), and it is a more potent NMDA blocker than ketamine (relative potency order MK-801 > PCP > tiletamine > ketamine). It is also longer-acting than ketamine, but on its own it produces poor muscle relaxation, marked rigidity and a rough, sometimes convulsive recovery. For that reason it is almost never given alone: the marketed product Telazol (US) / Zoletil (elsewhere) combines it 1:1 with the benzodiazepine zolazepam, which smooths induction and recovery and counters the muscle rigidity and seizures, giving roughly half an hour of surgical anaesthesia. Tiletamine has a single quaternary stereocentre and is used as the racemate (the enantiomers are depicted here, but no single-enantiomer preparation is marketed). It is metabolised in the liver and excreted renally.

Biological targets

  • NMDA
Pharmacokinetics
BioavailabilityNot reported
TmaxNot reported
Half-lifeSpecies-dependent, longer-acting than ketamine
VdNot reported
Protein bindingNot reported
MetabolismHepatic
ExcretionRenal
Toxicology & Safety
Harm-reduction note: Toxicity and risk depend on dose, route, purity, combinations, setting, and individual health factors. Missing harms should never be interpreted as evidence of safety.

Not reported

Tiletamine is a potent veterinary dissociative anaesthetic with a narrow, species-dependent safety margin and no role in human medicine. Used alone it causes muscle rigidity, tremor and frank convulsions and a prolonged, rough (sometimes delirious) recovery: the reason it is marketed only in combination with zolazepam. It depresses breathing and can cause apnoea and cardiovascular changes (raised heart rate and blood pressure, arrhythmias), excessive salivation, hyperthermia and increased intracranial and intraocular pressure. Recovery can be violent, with hypersensitivity to noise and touch. Human exposure is almost always through diversion of the veterinary product and is dangerous: doses are formulated for animals, the dissociation is intense and unpredictable, and, as with ketamine and PCP, aspiration and injury under anaesthesia are real risks. A recent case report described severe tremors after tiletamine e-cigarette use with alcohol. It is contraindicated in animals with significant cardiac, renal, pancreatic or CNS disease and in hyperthyroidism, and any co-use with alcohol or other CNS depressants adds respiratory-depression risk.[2]

Legal Status
Legal note: Legal status can change over time and may vary by country, region, formulation, analogue status, prescription context, and enforcement practice. Always confirm with current official sources before relying on this section.
Interactions & Contraindications

Drug interactions

Alcohol, Opioids, Benzodiazepines Additive sedation and respiratory depression.[2]
General anaesthetics and other sedatives Additive cardiorespiratory depression with other anaesthetics and sedatives.[2]

Contraindications

Cardiovascular disease, hypertension or arrhythmia significant cardiac disease.[2]
Kidney or liver impairment renal or pancreatic disease.[2]
Current or prior seizure disorder CNS signs or seizure disorders.[2]
Hyperthyroidism[2]
Combining with alcohol or other CNS depressants concurrent alcohol or other CNS depressants.[2]
Usage & Context
  • A veterinary injectable anaesthetic, used almost exclusively as the fixed combination with zolazepam (Telazol/Zoletil) for chemical restraint and surgical anaesthesia in cats, dogs and wildlife.
  • Originally developed (as CI-634) in the 1960s search for ketamine-like anaesthetics. It proved too rigidity- and seizure-prone for human use.
  • Occasionally misused recreationally through diversion of the veterinary product, but this is rare and hazardous.
Sources & Evidence

Further Information