Final Exam Pathophysiology

Correct Answer: A

Rationale: The correct answer is A. Sildenafil is contraindicated in patients taking nitrates due to the risk of severe hypotension. Nitrates and sildenafil both cause vasodilation, leading to a synergistic effect that can result in a dangerous drop in blood pressure. Choices B, C, and D are incorrect because there is no specific contraindication for taking sildenafil with food, having a history of hypertension, or taking it with grapefruit juice. The main concern is the concurrent use of nitrates with sildenafil.

Correct Answer: C

Rationale: In this scenario, a decubitus ulcer on the coccyx indicates a breakdown of the skin's integrity due to prolonged pressure. The skin is the primary defense mechanism of the body against external pathogens. When the skin is compromised, it can lead to infections and other complications. The mucous membrane (Choice A) plays a role in protecting internal surfaces, not the skin. The respiratory tract (Choice B) is involved in breathing and not directly related to the skin's defense. The gastrointestinal tract (Choice D) is responsible for digestion and absorption of nutrients, not the primary defense mechanism against external threats like the skin.

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: C

Rationale: The correct answer is C. Oral contraceptives can be less effective when taken with certain antibiotics as they may interfere with the contraceptive's efficacy, potentially leading to decreased effectiveness. Therefore, patients should be advised to use additional contraception methods if they are also taking antibiotics. Choice A is incorrect because while oral contraceptives are highly effective, they are not 100% foolproof. Choice B is incorrect as oral contraceptives may take some time to reach their full effectiveness after starting. Choice D is incorrect since taking oral contraceptives with food does not necessarily impact their effectiveness.

Correct Answer: B

Rationale: The correct answer is B, Hemolytic anemia. Normocytic-normochromic anemia is a type of anemia characterized by normal-sized and normal-colored red blood cells. Hemolytic anemia is a condition where red blood cells are destroyed prematurely, leading to normocytic-normochromic anemia. Sideroblastic anemia (Choice A) is characterized by ringed sideroblasts in the bone marrow. Pernicious anemia (Choice C) is due to vitamin B12 deficiency. Iron deficiency anemia (Choice D) is characterized by microcytic-hypochromic red blood cells.