Final answer:
Benzodiazepines enhance GABA binding to its receptors, while barbiturates directly activate GABA receptors. Both have sedative, hypnotic, and anticonvulsant effects, but benzodiazepines are safer.
Step-by-step explanation:
The MOA (mechanism of action) of benzodiazepines and barbiturates involves the enhancement of the inhibitory neurotransmitter gamma-Aminobutyric acid (GABA) in the brain. Benzodiazepines enhance the binding of GABA to its receptors, leading to increased inhibitory effects and reduced neuronal activity. Barbiturates also enhance GABA activity, but they do so by directly activating the GABA receptors themselves.
For example, benzodiazepines like diazepam (Valium) increase the affinity of the GABA receptors for GABA, which increases the inhibitory effects of GABA. Barbiturates like phenobarbital directly activate the GABA receptors, producing a similar inhibitory effect.
Both drugs have sedative, hypnotic, and anticonvulsant effects, but benzodiazepines are generally considered safer due to a lower risk of overdose and addiction compared to barbiturates.