Tick the drug which is a 5-lipoxygenase inhibitor:

Correct Answer: C

Rationale: Step-by-step rationale: 1. 5-lipoxygenase is an enzyme involved in leukotriene synthesis. 2. Zileuton is a specific 5-lipoxygenase inhibitor. 3. Budesonide and Beclometazone are corticosteroids, not 5-lipoxygenase inhibitors. 4. Sodium cromoglycate is a mast cell stabilizer, not a 5-lipoxygenase inhibitor. Summary: Choice C (Zileuton) is the correct answer as it directly inhibits 5-lipoxygenase, which is crucial in leukotriene production. Choices A, B, and D are incorrect as they are not 5-lipoxygenase inhibitors but belong to different classes of medications.

Correct Answer: D

Rationale: The correct answer is D: Quinidine. Quinidine is a Class IA antiarrhythmic drug that works by blocking sodium channels, prolonging the action potential duration, and delaying repolarization in cardiac cells. This helps in treating atrial and ventricular arrhythmias. Sotalol (A) is a Class III antiarrhythmic drug, Propranolol (B) is a beta-blocker, and Verapamil (C) is a calcium channel blocker, not Class IA antiarrhythmics.

Correct Answer: D

Rationale: The correct answer is D: Minoxidil. Minoxidil is a direct-acting vasodilator, not a central-acting antihypertensive drug. Central-acting antihypertensive drugs like Methyldopa, Clonidine, and Moxonidine work by acting on the central nervous system to reduce sympathetic outflow, thereby lowering blood pressure. Minoxidil, on the other hand, works by directly relaxing smooth muscle cells in blood vessels, leading to vasodilation and reduced blood pressure. So, Minoxidil does not belong to the category of central-acting antihypertensive drugs.

Correct Answer: A

Rationale: The correct answer is A because vinpocetine is known to dilate cerebral vessels, leading to improved blood supply to the brain. This mechanism of action helps enhance cerebral circulation and oxygen delivery, thereby potentially improving cognitive function. Choice B is incorrect because vinpocetine does not constrict cerebral vessels and decrease blood supply. Choice C is incorrect as vinpocetine does not directly stimulate GABA-receptors to increase cerebral metabolic processes. Choice D is incorrect as vinpocetine does not constrict peripheral vessels and increase blood pressure.

Correct Answer: C

Rationale: The correct answer is C because human insulin can be given to patients who have an allergy to animal insulins. This is crucial as some patients may develop allergic reactions to animal insulins, making it unsafe for them to use. Human insulin, being a synthetic form, is less likely to trigger allergies in such patients. The other choices, A, B, and D, are incorrect as they do not address the primary reason for prescribing human insulin, which is the specific need for patients with allergies to animal insulins.