Which of the following drugs is used for acute toxic effects of organophosphate cholinesterase inhibitors?

Correct Answer: C

Rationale: Correct Answer: C (Pralidoxime) Rationale: 1. Pralidoxime reactivates inhibited cholinesterase enzymes. 2. This helps counteract the toxic effects of organophosphate cholinesterase inhibitors. 3. Atropine is used to treat the symptoms but does not directly counteract the toxic effects. 4. Pilocarpine and edrophonium are not used for acute toxic effects of organophosphate poisoning.

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: B

Rationale: The correct answer is B because propranolol does not reduce blood flow to the brain. Propranolol is a non-selective beta-blocker that decreases cardiac work and oxygen demand (choice A), inhibits renin secretion (choice C), and increases the atrioventricular nodal refractory period (choice D). By blocking beta receptors in the heart and blood vessels, propranolol reduces heart rate, contractility, and blood pressure, leading to decreased oxygen demand. Inhibiting renin secretion helps lower blood pressure. Increasing the atrioventricular nodal refractory period can slow down the conduction of electrical impulses in the heart, helping to control heart rhythm. Therefore, choices A, C, and D are all accurate effects of propranolol on the cardiovascular system.

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.