1. Neuroleptics

Question 1

What groups of drugs neuroleptics include?

Answer 1

Phenothiazine derivatives + butiriphenones

Question 2

What drugs belong to phenothiazine derivatives?

Answer 2

• Acepromazine
• Chlorpromazine
• Propionylpromazine

Question 3

Mechanism of action of phenothiazines (receptors)

Answer 3

Antagonist of:
* Dopaminergic receptor (D2) -› antipsychotic, antiemetic effect
* α-adrenoreceptor -› hypotension, sedation
* muscarinic receptor (mainly side effects)
* H1 receptor -› sedation, antiemetic effect
* 5HT receptor (enhancement of other effects)

Question 4

Pharmacological effects of phenothiazine derivatives:

Answer 4

• sedation (catalepsy-like immobilization)
• potentiation
• antiemetic effect
• inhibition of regulation of body temperature

Question 5

Pharmacokinetics of phenothiazines

Answer 5

• Poor oral absorption
• Good tissue distribution
• Slow onset of activity
• Long duration
• 95% of plasma protein binding
• Metabolism in liver
• Excretion via urine, in metabolites
• Slow elimination from the body, long WP

Question 6

Side effects of phenothiazines

Answer 6

• Hypotension (not for dehydrated or in shock)
• Hypothermia
• Tissue irritation, allergy, liver damage
• Penile prolapse (horses) and third eyelid prolapse (pets)
• Epilepsy
• Prolactin↑
• FSH, LH, ADH and oxytocin↓

Question 7

Main usage of phenothiazines

Answer 7

• calming during veterinary investigation and transport
• decrease of motor activity
• premedication

Question 8

Contraindications for phenothiazine derivatives:

Answer 8

• dehydrated animals
• shock
• epileptic animals
• pseudopregnant animals

Question 9

Chlorpromazine

Answer 9

• frequent side effects
• tissue irritation
• paradox reaction in horses

Question 10

Acepromazine

Answer 10

more efficacious than chlorpromazine, less side effects, better oral bioavailability

Question 11

Propionylpromazine

Answer 11

more reliable than chlorpromazine, less side effects

Question 12

Is oral absorption of phenothiazine tranquillisers good?

Answer 12

No. F = 0,2. Better in buccal, rectal use
Also IV, IM application

Question 13

Do phenothiazines cross BBB?

Answer 13

Yes -> good tissue distribution

Question 14

What is onset of activity for phenothiazines?

Answer 14

Slow onset. Long duration (10-12 hours)

Question 15

Drugs belonging to butirophenones:

Answer 15

• AZAPERONE
• Droperidol
• Fluanisone

Question 16

Mechanism of action of butirophenones:

Answer 16

• D2 inhibitors
• NA inhibitors
• Anticholinergic effects in CNS
• weak antagonists on alpha1 and H1 receptors

are more potent than phenothiazine derivatives, have some analgesic effects

applied only IM

Question 17

Which neuroleptic drug targets swine? What group of CNS depressants?

Answer 17

Azaperone. Butirophenones

Used in combination with metomidate

Question 18

Side effects, contraindications of butirophenons

Answer 18

• salivation or panting
• hypotension
• boar penile prolapse
• avoid use in cold conditions