General Anaesthesia

Question 1

MOA of thiopental

Answer 1

Thiopental binds to GABA receptors and potentiates GABA by increasing the DURATION of GABA-gated Cl- channel opening

Thiopental also acts on AMPA receptors, decreasing glutamate-mediated excitation

Question 2

MOA of benzodiazepines

Answer 2

Benzodiazepines potentiate GABAergic inhibition by increasing the efficiency of GABA, without directly activating GABA receptors, through and increase in FREQUENCY of GABA-gated Cl- channel opening. (it is GABA-dependent, no direct action on GABA unlike barbiturates)

Question 3

MOA of propofol

Answer 3

Potentiates GABA receptor activity, increases the duration of GABA-gated Cl- channel opening

Question 4

MOA of ketamine

Answer 4

NMDA receptor antagonist producing dissociated anaesthesia