Changes

==Mechanism of Action==

==Mechanism of Action==

Barbituates act by depressing the central nervous system (CNS) by acting at the Gamma Aminobutyric Acid A  receptors (GABAa). They mimic and enhance GABA, which is the principle inhibitory neurotransmitter in the CNS. Once bound to the GABAa receptor they reduce the rate of GABA dissocation and thereby increase chloride conductance. This results in hyperpolarisation of the membrane and reduced neuronal excitability, giving a sedative effect. However, as the concentration of barbituate increases, it starts to have a direct effect on the chloride conductance and this is thought to bring about the anaesthetic effects. Barbiturates depress the motor centres, conferring anticonvulsant activity, and the sensory centres, inducing anaesthesia.

Barbituates act by depressing the central nervous system (CNS) by acting at the Gamma Aminobutyric Acid A  receptors (GABAa). They mimic and enhance GABA, which is the principle inhibitory neurotransmitter in the CNS. Once bound to the GABAa receptor they reduce the rate of GABA dissocation and thereby increase chloride conductance. This results in hyperpolarisation of the membrane and reduced neuronal excitability, giving a sedative effect. However, as the concentration of barbituate increases, it starts to have a direct effect on the chloride conductance and this is thought to bring about anaesthetic effects. Barbiturates depress the motor centres, conferring anticonvulsant activity, and the sensory centres, inducing anaesthesia.

==Pharmacologic Considerations==

==Pharmacologic Considerations==