Which of the following drugs is used in treatment of morphine or heroin addiction:

Correct Answer: B

Rationale: Methadone (choice B), a long-acting mu agonist, is used in opioid addiction (e.g., morphine, heroin) to stabilize patients, reduce cravings, and prevent withdrawal during detoxification or maintenance. Its slow onset and long half-life minimize euphoria, aiding controlled tapering. Butorphanol (choice A), a mixed agonist-antagonist, isn't standard for addiction due to limited mu agonism. Alfentanil (choice C), a short-acting opioid, is for anesthesia, not addiction. Dextropropoxyphene (choice D), a weak opioid, lacks efficacy for addiction management. Methadone's role is well-established, balancing efficacy and safety in addiction therapy, a key pharmacological strategy.

Correct Answer: D

Rationale: Benzodiazepines (e.g., diazepam) relax muscles (choice A), sedate/hypnotize (choice B), and control seizures (choice C) via GABAa potentiation. Hepatic microsomal enzyme induction (choice D) is typical of barbiturates or phenytoin, not benzodiazepines, which are metabolized but don't induce enzymes significantly. This exception differentiates their pharmacology.

Correct Answer: D

Rationale: Diazepam (choice A), a benzodiazepine, reduces anxiety via GABA. Buspirone (choice B), a 5-HT1A agonist, offers non-sedating anxiolysis. Propranolol (choice C), a beta-blocker, manages physical symptoms (e.g., tachycardia). ‘All of the above' (choice D) reflects their combined utility in anxiety, covering acute and chronic needs.

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.