Phenothiazines

PHENOTHIAZINES

Phenothiazines: Chlorpromazine, Acepromazine, Promethazine, Triflupromazine.

Mainly used as a tranquilizers (ataratics or neuroleptics) that relieve anxiety without undue sedation facilitating quietening and handling of animals.

  • Wide range of central and peripheral effects – act on dopamine, norepinephrine, 5HT and histamine receptors.
  • Decrease spontaneous motor activity
  • Depress the brain stem and connections to the cortex
  • At high doses catalepsy is produced – animals remain immobile at a fixed position for a long time
  • Powerful antiemetic action
  • Antiadrenergic action on heart result in Cardiovascular collapse
  • Chlorpromazine –(Largactil) – prototype drug which was popular in human and veterinary medicine. 
  • Widely used in humans for antipsychosis
  • Acepromazine – popular drug
  • Good sedative – lasts 4 – 6 h but much high reported in dogs
  • May show initial excitement
  • Also cause hypothermia and antiemetic effect
  • Causes paralysis of the retractor penis resulting in  priapism and paralysis of the penis in stallion and bulls and affect their market value
  • Also causes prolapse of third eyelid
  • Used as antispasmodic in colic in horses
  • Used as a sedative premedication
  • Also in pets for antiemesis
  • Promethazine – used as an antihistaminic
  • Triflupromazine (Siquil) as a sedative, as a restraint and as a preanaesthetic
  • Methotripromazine – agent with significant analgesic action
Last modified: Wednesday, 16 May 2012, 4:35 AM