All of the following drugs destroy disulfide bonds of proteoglycans which causes depolymerization and reduction of viscosity of sputum EXCEPT:

Correct Answer: C

Rationale: The correct answer is C: Desoxiribonuclease. Desoxiribonuclease is an enzyme that breaks down DNA, not disulfide bonds of proteoglycans. A: Acetylcysteine breaks disulfide bonds, reducing sputum viscosity. B: Ambroxol disrupts disulfide bonds, aiding in sputum clearance. D: Bromhexin also works by disrupting disulfide bonds, facilitating mucus clearance.

Correct Answer: C

Rationale: Rationale: C is the correct answer because cardiac glycoside-induced ventricular tachyarrhythmias are more common in patients with hypokalemia, not hyperkalemia. This is due to the increased sensitivity of the myocardium to glycosides in the setting of low potassium levels. A: Lidocaine is not the drug of choice for treating these arrhythmias; instead, antiarrhythmic medications like phenytoin or amiodarone are preferred. B: Digibind (Digoxin-specific antibody) is used in severe cases to reverse the effects of cardiac glycosides. D: Patients with heart failure or preexisting heart damage are at higher risk for developing these arrhythmias due to impaired cardiac function and increased susceptibility to glycoside toxicity.

Correct Answer: A

Rationale: Step 1: Dipyridamole is a phosphodiesterase inhibitor that increases cyclic adenosine monophosphate (cAMP), leading to coronary vasodilation. Step 2: Myotropic agents act directly on vascular smooth muscle to cause vasodilation. Step 3: Dipyridamole's mechanism fits the definition of a myotropic coronary dilator. Summary: Atenolol (C) is a beta-blocker that works by blocking beta-adrenergic receptors. Validol (B) is a menthol-based preparation for angina relief. Alinidine (D) is a selective I1-agonist used for hypertension, not as a coronary dilator.

Correct Answer: A

Rationale: The correct answer is A because dopamine in high doses primarily acts on alpha-adrenoreceptors, leading to peripheral vasoconstriction. This is known as the "pressor effect" of dopamine. Dopamine does not directly act on its own receptors (choice B) for vasodilation. While dopamine can also stimulate beta-1 adrenoreceptors (choice C) to enhance cardiac output, this is not the main effect in high doses. Choice D is incorrect because dopamine primarily influences alpha-adrenoreceptors, not all of the listed receptors.

Correct Answer: D

Rationale: The correct answer is D because iodism refers to the adverse effects of excessive iodine intake, not a situation where iodide preparations are used. A: Iodide is used in thyroid disorders to regulate thyroid hormone production. B: Iodide can be used in granulomatous lesions like Syphilis due to its anti-inflammatory properties. C: Iodide is used as an antiseptic due to its antimicrobial properties. In summary, iodide preparations are used in various medical conditions except for causing iodism.