Actoprotectors are:

Correct Answer: A

Rationale: The correct answer is A because actoprotectors are substances that improve physical efficiency by enhancing endurance, stamina, and overall physical performance. This is supported by scientific evidence showing their positive effects on exercise capacity and fatigue resistance. Choice B is incorrect because cognition enhancers focus on improving cognitive functions, not physical performance. Choice C is incorrect as actoprotectors do not raise non-specific resistance towards stresses but specifically target physical efficiency. Choice D is incorrect because actoprotectors do not directly stimulate respiratory and vasomotor centers in the brain, but rather enhance physical capabilities.

Correct Answer: D

Rationale: The correct answer is D: None of the above. In patients with airway problems, the induction agent of choice is usually propofol. Desflurane (A) and nitrous oxide (B) are not ideal for patients with compromised airways due to their irritant properties and potential for airway reactivity. Halothane (C) is not recommended in patients with airway problems due to its potential for respiratory depression and airway irritation. Therefore, the correct choice is D as propofol is the preferred induction agent in patients with airway issues.

Correct Answer: A

Rationale: The correct answer is A: Misoprostol. Misoprostol is an analog of prostaglandin E1, as it shares similar pharmacological properties. Prostaglandin E1 helps protect the stomach lining and promotes healing of ulcers. Misoprostol, by mimicking prostaglandin E1, can be used to prevent and treat ulcers caused by NSAIDs. De-nol (B) and sucralfate (C) work differently by forming a protective barrier over ulcers. Omeprazole (D) is a proton pump inhibitor that reduces stomach acid production, not an analog of prostaglandin E1.

Correct Answer: A

Rationale: The correct answer is A: Low. Low doses of Aspirin are more effective in inhibiting Thromboxane A2 because they irreversibly inhibit cyclooxygenase-1 in platelets, which is necessary for Thromboxane A2 synthesis. High doses can lead to non-specific inhibition of COX-1 and COX-2, which may cause side effects. Choice B is incorrect because high doses can lead to non-specific inhibition. Choice C is incorrect because high doses are not more effective. Choice D is incorrect as low doses are effective.

Correct Answer: C

Rationale: The correct answer is C, both Nifedipine and Verapamil are contraindicated in patients with moderate to severe heart failure due to their negative inotropic effects. These drugs can worsen heart failure symptoms by further reducing cardiac output. Nifedipine and Verapamil are calcium channel blockers that can lead to decreased contractility of the heart muscle, exacerbating heart failure. Choice A (Nifedipine) and choice B (Verapamil) are incorrect because they can be harmful in patients with heart failure. Choice D (None of the above) is incorrect as both drugs should be avoided in this patient population.