A 17-year-old woman has come to the clinic requesting emergency contraception after having unprotected sex 24 hours ago. What medication is the clinician most likely to prescribe?

Correct Answer: A

Rationale: The correct answer is A: Levonorgestrel (Plan B). Levonorgestrel is the most commonly prescribed medication for emergency contraception within 72 hours of unprotected intercourse. It is effective when taken within 72 hours after intercourse, with better efficacy the sooner it is taken. Choice B, Mifepristone (RU-486), is not indicated for emergency contraception but is used for medical abortion. Choice C, Ulipristal acetate (ella), is another option for emergency contraception that is effective up to 120 hours after unprotected intercourse. Choice D, Estradiol (Estrace), is not used for emergency contraception.

Correct Answer: A

Rationale: The correct answer is A. Tamoxifen increases the risk of venous thromboembolism, a serious side effect, so patients should be educated about the signs and symptoms of blood clots. This information is crucial as early recognition and prompt treatment of blood clots can prevent complications. Choices B, C, and D are incorrect because tamoxifen is not associated with causing weight gain, decreasing the risk of osteoporosis, or increasing the risk of breast cancer. Providing accurate information is essential for patient safety and understanding.

Correct Answer: D

Rationale: A rash from poison ivy is an example of a type IV hypersensitivity reaction. Type IV hypersensitivity reactions are delayed cell-mediated immune responses involving T cells. This type of reaction is characterized by a delayed onset, typically occurring 48-72 hours after exposure to the antigen. Choice A, Type I hypersensitivity reactions, are immediate hypersensitivity reactions mediated by IgE antibodies. Choices B and C, Type II and Type III hypersensitivity reactions, involve antibody-mediated cytotoxicity and immune complex deposition, respectively, which are not characteristic of poison ivy-induced rashes.

Correct Answer: C

Rationale: A chest x-ray is the most appropriate diagnostic test for a client with a history of tuberculosis experiencing a recurrence of symptoms. A chest x-ray is commonly used to visualize the lungs and check for signs of active tuberculosis, such as abnormal shadows or nodules. While a sputum culture (Choice A) can confirm the presence of TB bacteria, it may not be the initial test ordered for a recurrence. Bronchoscopy (Choice B) and CT scan of the chest (Choice D) are more invasive and usually reserved for cases where the chest x-ray is inconclusive or to further assess complications, rather than as the initial diagnostic test for a recurrence of tuberculosis.

Correct Answer: B

Rationale: The correct answer is B. Raloxifene, such as Evista, works by decreasing bone resorption and increasing bone density. This medication is beneficial in the prevention and treatment of osteoporosis by slowing down the breakdown of bone tissue, thereby reducing the risk of fractures. Choices A, C, and D are incorrect because raloxifene does not directly stimulate the formation of new bone, increase calcium absorption in the intestines, or increase the excretion of calcium through the kidneys.

Correct Answer: A

Rationale: When itraconazole is administered with carbamazepine, itraconazole may increase the serum levels of carbamazepine, potentially leading to toxicity. Therefore, choice A is correct. Discontinuing carbamazepine (choice B) or changing the antiseizure medication (choice C) is not necessary unless advised by a healthcare provider. Choice D, requiring a higher dosage of itraconazole, is not accurate in this scenario.

Correct Answer: B

Rationale: The correct answer is B: 'Use of nitrates.' Tadalafil (Cialis) is contraindicated in patients using nitrates due to the risk of severe hypotension. Nitrates and tadalafil both cause vasodilation, leading to a synergistic effect that can result in a dangerous drop in blood pressure. Choices A, C, and D are incorrect because a history of hypertension, the use of antihypertensive medications, and a history of peptic ulcer disease are not direct contraindications for tadalafil use.

Correct Answer: B

Rationale: The correct answer is B. HIV is a retrovirus that infects T cells and leads to the gradual destruction of the immune system. Choice A is incorrect because HIV infects T cells primarily, not just B cells. Choice C is incorrect because HIV infection requires host cell receptors for entry. Choice D is incorrect because cell death after HIV infection is not immediate; instead, the virus gradually weakens the immune system over time.

Correct Answer: C

Rationale: The correct answer is C. Caseous necrosis is characteristic of tuberculosis, where the tissue has a soft, cheese-like appearance. Coagulative necrosis involves protein denaturation, liquefactive necrosis is seen in brain infarcts and abscesses, and autonecrosis is not a recognized term in pathology, making them incorrect choices in this scenario.