A patient receiving isoniazid (INH) and rifampin (Rifadin) has a decreased urinary output and decreased sensation in his great toes. Which laboratory values should be assessed?

Correct Answer: C

Rationale: In a patient receiving isoniazid (INH) and rifampin (Rifadin) with symptoms of decreased urinary output and decreased sensation in great toes, assessing urine culture and sensitivity is crucial. These symptoms could indicate peripheral neuropathy, a known side effect of isoniazid, and rifampin can cause renal toxicity. Checking for any urinary tract infection or drug-induced nephrotoxicity is important. Choices A, B, and D are incorrect as they do not directly address the symptoms presented by the patient or the potential side effects of the medications mentioned.

Correct Answer: C

Rationale: The correct answer is C: The hypothalamus. The hypothalamus plays a central role in regulating endocrine and autonomic functions, including fluid and electrolyte balance. In this case, the girl's symptoms of deficits in endocrine and autonomic nervous system control, along with fluid and electrolyte imbalances, point towards dysfunction in the hypothalamus. Choices A, B, and D are incorrect because the thalamus is mainly involved in sensory relay, the pituitary gland regulates various hormones but is controlled by the hypothalamus, and the midbrain is responsible for motor control and arousal, not endocrine or autonomic functions.

Correct Answer: B

Rationale: The correct answer is B. Tinidazole (Tindamax) is known to cause a bitter or metallic taste in the mouth. This side effect is common and indicates that the patient understands the medication they are taking. Choices A, C, and D are incorrect because they do not specifically relate to the common side effects or administration details of tinidazole.

Correct Answer: C

Rationale: The expected outcome of acyclovir (Zovirax) for the treatment of genital herpes is decreased viral shedding. Acyclovir is an antiviral medication that works by inhibiting the replication of the herpes virus, thereby reducing viral shedding and helping to control outbreaks. Choice A, decreased testosterone production, and Choice B, decreased libido, are unrelated outcomes of acyclovir treatment for genital herpes. Choice D, decreased bacterial replication, is also incorrect as acyclovir specifically targets viruses and does not affect bacterial replication.

Correct Answer: D

Rationale: A biopsy is the most appropriate method for diagnosing lung cancer in its early stages. A biopsy involves taking a small tissue sample from the lung for examination under a microscope. This method provides a definitive diagnosis by identifying cancerous cells. CT scans, MRIs, and X-rays can help detect abnormalities in the lungs, but a biopsy is necessary to confirm the presence of lung cancer. CT scans offer detailed images of the lung's structure, MRIs use magnetic fields for imaging soft tissues, and X-rays provide a basic view of the lungs, but none of these imaging techniques can definitively confirm the presence of cancer without a biopsy.

Correct Answer: B

Rationale: In this scenario, where impaired erythropoiesis is suspected, the most clinically relevant laboratory studies would focus on red blood cell parameters. Therefore, assessing RBC count, hemoglobin levels, and hematocrit values would provide direct insights into erythropoiesis. Choices A, C, and D are not directly related to erythropoiesis assessment. White blood cell count with a differential is more indicative of immune response and infection. INR and aPTT are coagulation studies, while d-dimer and C-reactive protein levels are more associated with inflammation and thrombotic events.

Correct Answer: A

Rationale: The correct answer is A: Decreased urinary frequency and urgency. Finasteride is expected to decrease urinary frequency and urgency in patients with BPH by reducing prostate size. It works by inhibiting the enzyme that converts testosterone to dihydrotestosterone, which helps shrink the prostate gland. Choices B, C, and D are incorrect. Finasteride does not increase prostate size, blood pressure, or the risk of kidney stones.

Correct Answer: A

Rationale: The correct answer is A: Use of nitrates. Tadalafil (Cialis) is contraindicated in patients taking nitrates due to the risk of severe hypotension. Nitrates potentiate the hypotensive effects of tadalafil, leading to a potentially life-threatening drop in blood pressure. Choices B, C, and D are incorrect because antihypertensive medications, history of hypertension, and history of peptic ulcer disease are not critical contraindications for tadalafil use. While caution may be needed in patients with certain conditions, the highest priority is addressing the interaction with nitrates.

Correct Answer: A

Rationale: The correct answer is A. Raloxifene works by decreasing bone resorption and increasing bone density. This helps in preventing further bone loss and reducing the risk of fractures in patients with osteoporosis. Choice B is incorrect because raloxifene does not stimulate the formation of new bone, but rather helps to maintain existing bone mass. Choice C is incorrect as raloxifene does not directly increase calcium absorption in the intestines. Choice D is also incorrect as raloxifene does not increase the excretion of calcium through the kidneys.