Isoproterenol is:

Correct Answer: D

Rationale: Isoproterenol is a nonselective beta receptor agonist. It activates both beta1 and beta2 adrenergic receptors. This is because it has a higher affinity for beta receptors compared to alpha receptors, making it nonselective. Therefore, option D is correct. Option A is incorrect because isoproterenol does not significantly activate alpha receptors. Option B is incorrect as it is not beta1-selective. Option C is incorrect as isoproterenol activates both beta1 and beta2 receptors.

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: D

Rationale: The correct answer is D, All of the above. Phenytoin, Valproate, and Topiramate are known to have teratogenic effects. Phenytoin can cause fetal hydantoin syndrome, Valproate is associated with neural tube defects, and Topiramate can lead to cleft lip and palate. These antiseizure drugs should be used cautiously in pregnant women due to the potential harm to the developing fetus. The other choices are incorrect because only Phenytoin, Valproate, and Topiramate are specifically linked to teratogenicity.

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.