Final Exam Pathophysiology

Correct Answer: B

Rationale: In patients with chronic renal failure, especially in older adults, dosages of medications excreted renally need to be adjusted based on kidney function. Acyclovir is primarily eliminated by the kidneys, so in a patient with chronic renal failure, the dose would need to be smaller to prevent drug accumulation and toxicity. Choice A is incorrect because the dose adjustment is more related to the patient's kidney function than the presence of herpes simplex. Choice C is incorrect because the type of herpes infection does not determine the dose adjustment for acyclovir. Choice D is incorrect as the creatinine clearance is a more accurate measure of kidney function compared to creatinine levels.

Correct Answer: B

Rationale: The correct answer is B because anabolic steroids are indeed universally dangerous, but they pose greater risks to adolescents due to their impact on growth and development. Choice A is incorrect because anabolic steroids do have the potential to build muscle mass, though not to the extent often portrayed in the media. Choice C is incorrect as muscle mass gained from steroid use may persist for a period even after discontinuation. Choice D is incorrect as anabolic steroids can enhance muscle performance initially, though long-term use can have adverse effects on health and not specifically on the ability to perform weight-bearing exercises.

Correct Answer: C

Rationale: The correct answer is C: IgE. A severe allergic reaction, such as the one experienced by the 10-year-old male after being stung by a bee, is mediated by IgE. IgE is involved in common allergic responses, triggering the release of histamine and other chemicals that lead to allergy symptoms. Choice A, Toxoids, are inactivated toxins used in vaccines. Choice B, IgA, is mainly found in mucosal areas and secretions, playing a role in mucosal immunity. Choice D, IgM, is the first antibody produced in response to an infection.

Correct Answer: A

Rationale: The correct answer is A: Diarrhea. Hepatotoxicity caused by isoniazid can present with various symptoms, including yellow discoloration of the sclera of the eyes, which indicates jaundice. Another common sign of hepatotoxicity is gastrointestinal symptoms such as nausea, vomiting, and diarrhea, which can occur due to liver dysfunction affecting bile production and digestion. Numbness (choice B) is more commonly associated with peripheral neuropathy caused by isoniazid, while diminished vision (choice C) and light-colored stools (choice D) are not typical manifestations of hepatotoxicity.

Correct Answer: A

Rationale: Amphotericin B is an antifungal medication that acts by binding to ergosterol, a component of fungal cell membranes, forming pores that disrupt the integrity of the membrane. This action leads to leakage of cellular contents and ultimately cell death. Choice B is incorrect as amphotericin B does not bind to an enzyme required for the synthesis of ergosterol. Choice C is incorrect as the drug primarily affects the cell membrane rather than the cell wall. Choice D is also incorrect as amphotericin B does not inhibit glucan synthetase.