Tick the drug used for trypanosomosis treatment:

Correct Answer: A

Rationale: The correct answer is A: Melarsoprol. Melarsoprol is an arsenical compound used specifically for the treatment of trypanosomosis, caused by Trypanosoma parasites. It is effective in treating both forms of the disease, African trypanosomiasis (sleeping sickness) and American trypanosomiasis (Chagas disease). Metronidazole (B) is used for treating anaerobic bacterial infections, not trypanosomiasis. Tetracycline (C) is an antibiotic effective against a wide range of bacterial infections, but not against trypanosomiasis. Quinidine (D) is used to treat malaria and certain heart rhythm disorders, but not trypanosomiasis.

Correct Answer: C

Rationale: The correct answer is C: Verapamil. Verapamil is a calcium channel blocker that can cause constipation, which is a common complaint in patients. Hydralazine (A) can cause reflex tachycardia, Propranolol (B) is a beta-blocker that can cause bradycardia, and Clonidine (D) is an alpha-2 agonist that can cause hypotension. Therefore, based on the patient's complaint of constipation, Verapamil is the most likely drug added to the patient's therapy.

Correct Answer: D

Rationale: The correct answer is D because discontinuing digoxin and starting losartan is the appropriate therapeutic adjustment for a 65-year-old man with acute distress and cardiac failure. Digoxin is not recommended in the acute phase of heart failure as it can worsen symptoms. Losartan, an angiotensin II receptor blocker, is beneficial in heart failure by improving outcomes and reducing hospitalizations. Discontinuing digoxin eliminates the risk of toxicity and adverse effects. Other choices are incorrect because adding potassium supplementation (Choice A) can increase the risk of hyperkalemia, adding atropine (Choice B) is not indicated in heart failure, and increasing furosemide dose (Choice C) may lead to electrolyte imbalances without addressing the underlying cause.

Correct Answer: B

Rationale: In this question, the correct answer is B) Mannitol. Mannitol is an osmotic diuretic that is poorly absorbed orally due to its physicochemical properties. Mannitol is a polar molecule that cannot easily pass through the gastrointestinal mucosa, leading to its negligible oral absorption. This property makes mannitol an effective agent for increasing urine flow without significant systemic effects when administered intravenously. Glycerin (Option A) and Isosorbide (Option C) are not osmotic diuretics like Mannitol. Glycerin is often used as a laxative and Isosorbide is commonly used in the treatment of angina and heart failure. They are absorbed through the gastrointestinal tract and exert their effects through different mechanisms than osmotic diuretics. Selecting "All of the above" (Option D) would be incorrect as not all the listed substances have negligible oral absorption as osmotic diuretics. This choice does not align with the specific pharmacological properties of each substance. In an educational context, understanding the absorption profiles of different drugs is crucial for pharmacology students and healthcare professionals. Knowing which drugs have negligible oral absorption can impact treatment decisions and dosing strategies. This question reinforces the importance of considering the pharmacokinetic properties of medications when prescribing them to patients.

Correct Answer: C

Rationale: The correct answer is C) Generation of an active metabolite. Amlodipine is a dihydropyridine calcium channel blocker that is primarily eliminated unchanged in the urine, with minimal hepatic metabolism. Therefore, it does not generate an active metabolite. Option A) High and consistent oral bioavailability is true for amlodipine, as it is well-absorbed orally and shows consistent plasma concentrations. Option B) Large volume of distribution is also a characteristic of amlodipine, as it has a high distribution into tissues. Option D) Long elimination half-life is another attribute of amlodipine, as it has a prolonged half-life allowing for once-daily dosing. Understanding the pharmacokinetic properties of cardiovascular drugs like amlodipine is crucial for healthcare professionals to make informed decisions regarding dosing, monitoring, and potential drug interactions. Knowing that amlodipine does not generate active metabolites helps in understanding its pharmacological profile and potential for drug-drug interactions compared to drugs that do undergo significant metabolism. This knowledge is essential for safe and effective pharmacotherapy in patients with cardiovascular conditions.