Zileutin prevents the production of leukotrienes. This statement is:

Correct Answer: A

Rationale: Step 1: Zileutin is a leukotriene synthesis inhibitor. Step 2: Leukotrienes are inflammatory mediators produced by the body. Step 3: By inhibiting leukotriene production, zileutin reduces inflammation. Step 4: Therefore, the statement "Zileutin prevents the production of leukotrienes" is TRUE. Summary: Choice A is correct because zileutin indeed prevents the production of leukotrienes, leading to reduced inflammation. Choices B, C, and D are incorrect as they do not accurately reflect the mechanism of action of zileutin.

Correct Answer: A

Rationale: Rationale: 1. Flecainide is classified as a Class IC antiarrhythmic drug based on Vaughan Williams classification. 2. Class IC drugs block sodium channels in cardiac tissue, slowing conduction. 3. Flecainide is used to treat ventricular arrhythmias. 4. Sotalol (Class III), Lidocaine (Class IB), and Verapamil (Class IV) belong to different antiarrhythmic classes. Summary: Sotalol is a Class III antiarrhythmic drug that blocks potassium channels. Lidocaine is a Class IB drug that blocks sodium channels. Verapamil is a Class IV drug that blocks calcium channels. These drugs have different mechanisms of action compared to Class IC drugs like Flecainide.

Correct Answer: C

Rationale: The correct answer is C: Trimethaphan. Trimethaphan is a ganglioblocking drug that acts on the autonomic nervous system by blocking nicotinic receptors in ganglia, reducing sympathetic outflow and lowering blood pressure. Hydralazine (A) is a direct vasodilator, Tubocurarine (B) is a neuromuscular blocker, and Metoprolol (D) is a beta blocker. These drugs do not act specifically on ganglia to lower blood pressure like Trimethaphan does.

Correct Answer: C

Rationale: The correct answer is C: Improving the microcirculation in cerebral tissue. Antiaggregants are used in disorders of brain circulation to prevent platelet aggregation and improve blood flow in the microcirculation of cerebral tissue. This helps to enhance oxygen and nutrient delivery to brain cells, ultimately improving brain function. Rationale: A: Stimulation of the metabolic processes in neurons is not the primary purpose of antiaggregants. While improved blood flow may indirectly support neuronal metabolism, the main goal of antiaggregants is to prevent clot formation and improve circulation. B: Dilation of cerebral vessels is not the main mechanism of action for antiaggregants. Although vasodilation can enhance blood flow, antiaggregants primarily work by preventing platelet aggregation rather than directly causing vessel dilation. D: All the above is incorrect because the primary purpose of antiaggregants in disorders of brain circulation is to improve microcirculation in cerebral tissue, not to stimulate metabolic processes in neurons or

Correct Answer: D

Rationale: In the context of pharmacology and insulin therapy, the correct statement about crystalline zinc (regular) insulin not being able to be administered orally (Option D) is justified due to its protein structure being destroyed in the gastrointestinal tract, rendering it ineffective if taken orally. Option A is incorrect as crystalline zinc insulin can indeed serve as replacement therapy for juvenile-onset diabetes, especially in cases where rapid-acting insulin is needed. Option B is also incorrect as crystalline zinc insulin is not typically administered intravenously; it is usually given subcutaneously for better absorption. Option C is incorrect as crystalline zinc insulin is classified as short-acting insulin due to its onset of action within 30 minutes to an hour, making it unsuitable for oral administration due to its rapid absorption rate. Educationally, understanding the routes of administration and characteristics of different types of insulin is crucial for healthcare professionals in managing diabetes effectively. It is essential for students to grasp the pharmacokinetics and pharmacodynamics of insulin to make informed decisions in clinical practice and provide optimal care for patients with diabetes.