A 66-year-old woman who has smoked two packs of cigarettes per day for 50 years has chronic bronchitis. She has tried to quit five times in the past but felt she could not go long without a cigarette. The nicotine in her cigarettes stimulates many cells in her body by binding certain receptors. Which of the following drugs blocks nicotinic receptors?

Correct Answer: C

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.

Correct Answer: B

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.

Correct Answer: B

Rationale: A competitive benzodiazepine receptor antagonist binds to the GABAa receptor's benzodiazepine site, preventing agonists like diazepam from exerting effects, without activating the receptor itself. Flumazenil is this antagonist, used to reverse benzodiazepine overdose (e.g., reversing sedation or respiratory depression) by competitively displacing agonists. Naloxone (choice A) is an opioid antagonist, targeting mu receptors to reverse opioid overdose, not benzodiazepine-related. Flurazepam (choice C) is a benzodiazepine agonist, promoting GABA effects, not blocking them. Disulfuram (choice D, likely misspelled) inhibits aldehyde dehydrogenase for alcoholism treatment, unrelated to benzodiazepine receptors. Flumazenil's specificity and competitive nature make it the correct choice. This question emphasizes antidote recognition, critical in emergency settings to counteract CNS depression, distinguishing it from other reversal agents like Naloxone.

Correct Answer: D

Rationale: Aspirin (acetylsalicylic acid) is used in acute rheumatic fever (choice D) for its anti-inflammatory and analgesic effects, reducing joint pain and inflammation in this autoimmune condition post-streptococcal infection. Vertigo (choice A) isn't an inflammatory condition aspirin targets. Peptic ulcer (choice B) is a contraindication, as aspirin exacerbates ulceration via COX-1 inhibition. Acute bronchial asthma (choice C) may worsen with aspirin due to leukotriene overproduction in sensitive patients. Acute rheumatic fever aligns with aspirin's anti-inflammatory utility, making it the correct therapeutic indication.

Correct Answer: C

Rationale: Fluoxetine (choice C), an SSRI, treats depression by selectively inhibiting serotonin reuptake, increasing synaptic levels. Imipramine (choice A) and Amitriptyline (choice B), tricyclic antidepressants, block multiple transmitters, not just serotonin. Maprotiline (choice D), a tetracyclic, primarily affects norepinephrine. Fluoxetine's specificity reduces side effects, making it a cornerstone in depression therapy.