Correct Answer: C

Rationale: The correct answer is C. Hormonal contraceptives increase blood levels of clotting factors, particularly factors II, VII, IX, and X. This elevation in clotting factors can predispose individuals to thromboembolic events, including blood clots. Choices A, B, and D are incorrect because hormonal contraceptives do not have a significant effect on serum triglycerides and cholesterol, platelet levels, or causing direct injury to blood vessel linings as the primary mechanism for clot formation.

Correct Answer: B

Rationale: The correct answer is B: 'It decreases bone resorption and increases bone density.' Raloxifene, as a selective estrogen receptor modulator (SERM), works by reducing bone resorption (breakdown) and maintaining or increasing bone density. This mechanism helps in preventing further bone loss and can even increase bone mass. Choices A, C, and D are incorrect. Raloxifene does not stimulate the formation of new bone (choice A), increase calcium absorption in the intestines (choice C), or increase the excretion of calcium through the kidneys (choice D).

Correct Answer: A

Rationale: The correct answer is A. Tamoxifen increases the risk of venous thromboembolism. Patients should be educated about signs and symptoms of blood clots, such as swelling, pain, or redness in the legs. Choices B, C, and D are incorrect because tamoxifen is not associated with decreasing the risk of osteoporosis, causing hot flashes and menopausal symptoms, or causing weight gain and fluid retention.

Correct Answer: B

Rationale: The correct answer is B: Metronidazole (Flagyl). When treating extraintestinal amebiasis, chloroquine is often used in combination with metronidazole to ensure the eradication of the parasite. Metronidazole helps to target the infection more effectively. Choices A, C, and D are incorrect. Iodoquinol (Yodoxin) is another antiprotozoal agent but is not typically used in combination with chloroquine for amebiasis. Metyrosine (Demser) is used in the management of pheochromocytoma, and carbamazepine (Tegretol) is an anticonvulsant and mood-stabilizing drug, neither of which are indicated for extraintestinal amebiasis.

Correct Answer: B

Rationale: The correct instruction the nurse should provide is to avoid taking nitrates while on sildenafil (Viagra). Combining sildenafil with nitrates can result in severe hypotension due to additive vasodilatory effects. Choice A is incorrect because sildenafil can be taken with or without food. Choice C is incorrect as there is no specific requirement to take sildenafil at bedtime. Choice D is incorrect as taking sildenafil with milk has not been shown to enhance its absorption.