Pharmacotherapeutic group: Nervous system, antipsychotics
ATCvet code: QN05AD90
Pharmacodynamic properties
Stresnil is a sedative butyrophenone neuroleptic with pronounced α-adrenergic properties for specific use in pigs.
Stresnil produces a predictable psychomotor sedation without narcosis after intramuscular administration. The degree of sedation is dose-related. Adult animals require comparatively lower doses than half-grown animals. At low doses (0.5 mg/kg), the animal is slightly sedated, yet it can be easily driven. With increasing doses, the animal becomes increasingly drowsy and slow. At 2 mg/kg, it lies down for about 2 hours, can hardly be driven and ceases to be aggressive. The induction period is short. Peak effect is reached after about 15 minutes in young animals and 30 minutes in adult animals. The duration of action is 1-3 hours, depending on the dose and the weight of the animal.
Pharmacokinetic particulars
Azaperone is rapidly absorbed from the injection site and peak concentrations in plasma occur within 1 hour after administration. The elimination from plasma is fast (T 1/2 = 2.5 h), due to the rapid and extensive metabolism and excretion.
The main 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.