Anxiolytic dosage reduction is recommended:

Correct Answer: D

Rationale: The correct answer is D, all of the above. Anxiolytic dosage reduction is recommended in patients taking cimetidine due to potential drug interactions. In patients with hepatic dysfunction, reduced metabolism can lead to increased drug levels. Elderly patients may be more sensitive to anxiolytics due to age-related changes in metabolism and increased risk of adverse effects. Therefore, all three factors (cimetidine use, hepatic dysfunction, and age) can influence anxiolytic dosing, making D the correct choice.

Correct Answer: B

Rationale: The correct answer is B: Zafirlucast, a leucotriene receptor antagonist. Leukotrienes are inflammatory mediators in asthma. Zafirlucast specifically blocks the action of leukotrienes by binding to their receptors, reducing inflammation and bronchoconstriction. Sodium cromoglycate (A) is a mast cell stabilizer, not a leukotriene receptor antagonist. Zileutin (C) inhibits 5-lipoxygenase, an enzyme involved in leukotriene synthesis. Triamcinolone (D) is a corticosteroid that acts through a different anti-inflammatory mechanism.

Correct Answer: C

Rationale: The correct answer is C: Activation of the antifibrinolytic system. This system is involved in clot dissolution, not bleeding control. Platelet adhesion, release, and triggering the coagulation process are essential physiological reactions that help control bleeding by forming a stable blood clot. Platelet adhesion allows platelets to stick to the site of injury, platelet release releases factors that promote clot formation, and triggering the coagulation process leads to the formation of fibrin strands that strengthen the clot. Therefore, choices A, B, and D are involved in the control of bleeding, while choice C is not.

Correct Answer: A

Rationale: Step 1: Class IC antiarrhythmic drugs work by blocking sodium channels to slow down conduction in the heart. Step 2: Flecainide is a Class IC antiarrhythmic drug that specifically blocks sodium channels effectively. Step 3: Sotalol (Choice B) is a Class III antiarrhythmic drug that blocks potassium channels. Step 4: Lidocaine (Choice C) is a Class IB antiarrhythmic drug that also blocks sodium channels, but it is not a Class IC drug. Step 5: Verapamil (Choice D) is a calcium channel blocker and not a Class IC antiarrhythmic drug. Summary: Flecainide (Choice A) is the correct answer as it is a Class IC antiarrhythmic drug that blocks sodium channels, while the other choices are different classes of antiarrhythmics with different mechanisms of action.

Correct Answer: C

Rationale: The correct answer is C: Guanethidine. Guanethidine is a sympatholytic drug that blocks the release of norepinephrine from sympathetic nerve terminals, thus reducing sympathetic activity. This leads to a decrease in blood pressure. A: Labetalol is a non-selective beta blocker with alpha-blocking activity. B: Prazosin is an alpha-1 adrenergic receptor antagonist. D: Clonidine is a centrally acting alpha-2 adrenergic agonist. Therefore, the correct choice for a sympatholytic drug is Guanethidine due to its mechanism of action in inhibiting sympathetic activity.