Azaperone is a neuroleptic sedative belonging to the butyrophenone class of pharmaceuticals. Butyrophenones work through the mechanism of central dopamine and peripheral adrenergic blockage to produce a strong anticholinergic effect. The other butyrophenone routinely used in wildlife is haloperidol as a longer acting tranquilizer.
Indications Wildlife Management:
Azaperone is most commonly used in combination with opiates and alpha-two agonists. In these combinations the dose is from 0.15 to 0.30 mg/kg body weight. If used alone the dose for sedation ranges from 0.5 to 2.0 mg/kg body weight depending on the species and desired level of effect. Combined with fentanyl alone it has been effective for use in sea otters.[Williams et al. 1981, J Wildl Dis 17(3): 337-342
In non-domestic species, azaperone has broad applications as a sedative or in combination with other drugs such as etorphine, fentanyl, and thiafentanyl oxalate (A3080) in immobilization and capture protocols. In New Zealand, it is used in an approved mixture with fentanyl and xylazine (Fentaz). It is routinely used in Africa as part of a sedation protocol for transport and environmental adaptation along with haloperidol and zuclopenthixol.
New uses of azaperone in the United States are being found in light of its recent availability as a compounded pharmaceutical. Additional species, uses and doses are found in the Handbook of Wildlife Chemical Immobilization (Kreeger et al.)
Indications in Domestic Species
Azaperone has a single use in domestic species as a sedative for swine.
Azaperone tartrate produces predictable psychomotor sedation without narcosis after intramuscular administration. It was developed for approval in domestic swine because of its pronounced sedative action, good tolerance and wide safety margin. Anti-shock activity of azaperone is 60 times higher than that of propionylpromazine and its adrenalytic action is 20 times lower.
Azaperone tartrate has the chemical structure of 4’-fluoro-[4-(2-pyridyl)-1- piperazinyl]-butyrophenone. It is light sensitive and should be protected from light and heat. In solution, its pH is approximately 4.
Azaperone is rapidly absorbed from the injection site with peak concentrations in plasma occurring within one hour after administration. Elimination from plasma is ½-2.5 hr. due to rapid and extensive metabolism. Metabolic pathways are 1) reduction of the butanone 2) oxidative N-dearylation 3) hydroxylation of the pyridine group. The target tissue for azaperone and its metabolites is the liver. Low residue levels are present in muscle and other edible tissues.
If used alone the dose for sedation is 0.5 to 2.0 mg/kg body weight depending on the species and desired level of effect. Uses and dose rates in combination with other drugs are found in
Recommended route of administration is deep intramuscular injection.
Azaperone was approved by the FDA in the 50 mg/ml concentration.
For use in swine it is compounded by ZooPharm in a concentration of 50 mg/ml.
Animals showed reduced activity for about 6 hours post-induction with azaperone. It should not be used in game species 30 days prior to a legal hunting season. The effects of azaperone are NOT reversed with the narcotic or alpha-two reversal agents. Animals may exhibit extra pyramidal signs at the higher dose rates.
Hyper-salivation and tachypnea may occur.
WARNING: Azaperone has no reversal, i.e. antagonist (antidote). Azaperone may cause hypotension and, at low doses, may cause excitement in equids.