CNS

Question 1

Benzodiazepines

Answer 1

Minor tranquillisers- sedative
Muscle relaxation
No analgesic effects
Stimulate GABA receptors
Eg Diazepam ad IV, Dist PPB, crosses BBB, first pass met. Ex kidney
Midazolam. Shorter acting

Question 2

A- agonists

Answer 2

Sedative won calming effect analgesic
Alpha r captors in forebrain associated with sleep and alertness
Primary side effect cvs depression
Can switch off noradrenaline release
Good visceral analgesic - colic 
Muscle relaxant 
Eg metetimidine, xylazine (short acting), detomidine (long acting) 
Lipid soluble, liver met, ex kidney

Question 3

Phenothiazine

Answer 3

Eg acepromazine (ACP)
Muscle relaxant
Strong sedative
Switches off a broad range of receptors within reticular activating system

Question 4

Local anaesthetics

Mechanism of action and examples

Answer 4

Block Na channels
Can cause bradycardia of gets into bloodstream
Procaine slow onset, short duration
Lidocaine fast onset medium duration
Bupivicaine moderate onset v.long duration

Question 5

Opioids
Receptors
With examples of drugs which act on these

Answer 5

Delta- hallucinations ( don’t want)
Mu- supraspinal analgesia
Kappa- spinal analgesia, sedation

Buprenorphine- partial against at mu, self limiting, harder to overdose
Butorphanol- mixed effect drug, agonist at kappa, but antagonist at mu.
Morphine, pethidine, fentanyl, mu agonists.

Etorphine mu and kappa agonist. Used as tranquilliser darts, antagonist naloxone

Question 6

Typical MOA for opioids

Answer 6

Inhibition of ca channels pre synaptic

Activation of k channels post synaptically