The most common use for azaperone is in relatively small doses as a "
serenic" (to reduce aggression) in farmed pigs, either to stop them fighting or to encourage sows to accept piglets. Higher doses are used for
anesthesia in combination with other drugs such as
xylazine,
tiletamine and
zolazepam. Azaperone is also used in combination with strong narcotics such as
etorphine or
carfentanil for tranquilizing large animals such as elephants. Use in horses is avoided as adverse reactions may occur. The
European Medicines Agency has established a
maximum residue limit for azaperone when administered to pigs. Azaperone (under the brand name
Stresnil) was approved for use in pigs in the USA in 1983, under NADA 115-732. ==Synthesis==