Four patients with chronic low back pain are being considered for treatment with a centrally acting analgesic. Tapentadol is the agent being considered for use. Which of the following challenging patients would best benefit from this agent?

Correct Answer: C

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

Correct Answer: C

Rationale: Acute salicylate (aspirin) intoxication causes hyperpyrexia (choice A) from uncoupled oxidative phosphorylation, hyperpnoea (choice B) from respiratory center stimulation, and metabolic acidosis in children (choice D) from acid accumulation. Pinpoint pupils (choice C), or miosis, are absent; salicylates don't affect pupil size like opioids, which cause miosis via mu receptors. Salicylate toxicity may cause tinnitus or confusion, but pupil effects aren't typical. This exception distinguishes salicylate poisoning from opioid overdose, aiding differential diagnosis in toxicology.

Correct Answer: A

Rationale: L-DOPA (choice A) treats Parkinsonism by crossing the blood-brain barrier and converting to dopamine, replenishing deficient levels. a-Methyldopa (choice B) lowers blood pressure, not Parkinsonism. Haloperidol (choice C), a dopamine antagonist, worsens it. Physostigmine (choice D), a cholinesterase inhibitor, aids cognition, not movement. L-DOPA's role is central to Parkinson's management.

Correct Answer: B

Rationale: Methadone (choice B), a long-acting mu agonist, stabilizes morphine addicts during withdrawal, reducing symptoms with its gradual onset and duration. Meperidine (choice A), Fentanyl (choice C), and Codeine (choice D), full agonists, lack the pharmacokinetic profile for controlled withdrawal, being shorter-acting or less suited. Methadone's role is pivotal in addiction therapy.

Correct Answer: C

Rationale: Alprazolam (choice C), a benzodiazepine, treats panic disorders by enhancing GABA, reducing acute anxiety. Thiopentone (choice A), an anesthetic, and Paraldehyde (choice B), a sedative, aren't for panic. Chlorpromazine (choice D), an antipsychotic, targets psychosis, not panic. Alprazolam's specificity is key.