Pharmacology III – CNS Module Practice Exam

Secobarbital is classified as a short-acting barbiturate, which makes B the correct choice. Barbiturates are central nervous system depressants that are used primarily for their sedative and hypnotic effects. Secobarbital, in particular, has a relatively short duration of action compared to other members of its class, making it effective for inducing sleep in patients with insomnia or for providing sedation prior to medical procedures.

The pharmacological properties of secobarbital allow it to enhance the effects of the neurotransmitter gamma-aminobutyric acid (GABA) at the GABA-A receptor, leading to increased neuronal inhibition. This results in sedation and potential sleep induction, which are characteristic mechanisms of short-acting barbiturates.

In contrast to long-acting benzodiazepines, which are known for their extended duration of effects often used for anxiety management, secobarbital's rapid onset and short duration make it distinct. Extended-release sedatives would have a different formulation and release profile, and antihistamines are primarily used for their effects in allergic reactions rather than sedation through mechanisms similar to barbiturates. Therefore, the classification of secobarbital as a short-acting barbiturate accurately reflects both