Select a hypnotic drug which is an imidazopyridine derivative:

Correct Answer: C

Rationale: The correct answer is C: Zolpidem. Zolpidem is an imidazopyridine derivative commonly used as a hypnotic drug for treating insomnia. This is because zolpidem acts specifically on the GABA-A receptor complex, binding to a distinct site that enhances the inhibitory effects of GABA neurotransmission, leading to sedative and hypnotic effects. A: Pentobarbital is a barbiturate, not an imidazopyridine derivative. B: Temazepam is a benzodiazepine derivative, not an imidazopyridine. D: Chloral hydrate is a sedative-hypnotic drug but not an imidazopyridine derivative. Therefore, the correct choice is C, Zolpidem, due to its unique pharmacological profile as an imidazopyridine derivative with specific GABA-A receptor activity.

Correct Answer: A

Rationale: Correct Answer: A Rationale: 1. Carbidopa cannot cross the blood-brain barrier due to its large molecular size. 2. Carbidopa inhibits peripheral DOPA decarboxylase, preventing levodopa breakdown outside the brain. 3. By reducing peripheral levodopa conversion, carbidopa increases levodopa availability to cross the blood-brain barrier. 4. This results in more levodopa reaching the brain for conversion to dopamine, enhancing its central effects. Summary: - Choice A is true as carbidopa indeed prevents peripheral levodopa breakdown, enhancing its central effects. - Choice B is incorrect because carbidopa does not act within the brain itself. - Choice C is incorrect as there is a correct answer. - Choice D is incorrect as not all statements are true.

Correct Answer: D

Rationale: The correct answer is D: Abstinence syndrome. These symptoms are characteristic of opioid withdrawal, which occurs when a person dependent on opioids suddenly stops or reduces their use. Rhinorrhea, lacrimation, chills, gooseflesh, and other symptoms listed are commonly seen during opioid withdrawal due to the body's reaction to the absence of the drug. Tolerance (A) refers to a decreased response to a drug over time, not withdrawal symptoms. Opioid overdosage (B) would present with different symptoms such as respiratory depression. Drug interactions (C) may lead to various side effects but wouldn't produce the specific withdrawal symptoms listed.

Correct Answer: B

Rationale: The correct answer is B: The pituitary. Dopamine inhibits prolactin release from the pituitary gland. Blockade of dopamine receptors in the pituitary leads to increased prolactin levels, causing hyperprolactinemia. Choices A, C, and D are incorrect as they are not directly involved in regulating prolactin release. A is related to nausea and vomiting control, C is associated with motor functions, and D is involved in reward and motivation pathways.

Correct Answer: C

Rationale: The correct answer is C because serotonin syndrome results from both increased stores of monoamine (serotonin) and significant accumulation of amine neurotransmitters in the synapses. - Increased stores of monoamine lead to excessive serotonin levels. - Significant accumulation of amine neurotransmitters in the synapses occurs due to excess serotonin being released and not being reabsorbed or broken down efficiently. Choice A alone is not sufficient as it does not address the synaptic accumulation aspect. Choice B alone is also not enough as it does not consider the role of increased stores of monoamine. Choice D is incorrect as serotonin syndrome is not caused by depleted stores of biogenic amines.