Which of the following hypnotic drugs causes least suppression of REM sleep?

Correct Answer: C

Rationale: The correct answer is C: Flurazepam. Flurazepam is a benzodiazepine hypnotic drug that causes the least suppression of REM sleep compared to the other options. Benzodiazepines like flurazepam enhance the quality of sleep without significantly disrupting REM sleep. Flumazenil (A) is a benzodiazepine receptor antagonist, not a hypnotic drug. Phenobarbital (B) and Secobarbital (D) are barbiturates that are known to suppress REM sleep significantly, unlike flurazepam. In summary, flurazepam is the best choice for a hypnotic drug that minimally affects REM sleep compared to the other options provided.

Correct Answer: C

Rationale: Rationale: 1. Kappa and delta agonists inhibit postsynaptic neurons by opening K+ channels. 2. They also close voltage-gated Ca2+ channels on presynaptic nerve terminals. 3. Therefore, choice C (Both a and b) is correct, as it encompasses both actions. Summary: - Choice A is incorrect because it only mentions the action of opening K+ channels. - Choice B is incorrect as it only refers to closing voltage-gated Ca2+ channels. - Choice D is unrelated to the actions of kappa and delta agonists on neuronal transmission.

Correct Answer: B

Rationale: The correct answer is B: Antipyretic effect. Non-narcotic agents, such as NSAIDs, have antipyretic properties, helping to reduce fever by acting on the hypothalamus. This is achieved without causing respiratory depression (A), euphoria (C), or physical dependence (D). NSAIDs work by inhibiting prostaglandin synthesis, which helps in reducing inflammation, pain, and fever without affecting the respiratory center or causing addictive tendencies. Thus, option B is the correct choice based on the pharmacological actions of non-narcotic agents.

Correct Answer: B

Rationale: Lithium carbonate is commonly used to treat bipolar disorder due to its mood-stabilizing effects. It helps regulate neurotransmitters in the brain, specifically serotonin and norepinephrine, which are implicated in mood regulation. For petit mal seizures, anti-epileptic drugs like ethosuximide are typically prescribed. Neurosis is treated through psychotherapy and medication targeting specific symptoms. Trigeminal neuralgia is usually managed with anticonvulsants like carbamazepine. In summary, lithium carbonate's mechanism of action aligns with the treatment goals of bipolar disorder, making it the correct choice.

Correct Answer: C

Rationale: The correct answer is C: General tonics. General tonics are CNS stimulants that help mitigate conditions of weakness or lack of tone in the entire organism or specific organs by providing a non-specific boost in energy and vitality. Psychostimulants (A) primarily target mental alertness and focus, not overall weakness. Analeptics (B) are CNS stimulants that specifically stimulate the respiratory centers and are not general tonics. Antidepressants (D) are used to treat mood disorders and do not directly address physical weakness or lack of tone.