Pentazocine is a mixed agonist-antagonist opioid used for moderate pain. Its receptor profile is best described as:

• A Full agonist at mu receptor and antagonist at kappa receptor
• B Agonist at kappa receptor and partial agonist/antagonist at mu receptor ✓
• C Full agonist at both mu and kappa receptors
• D Antagonist at mu receptor and agonist at delta receptor

Explanation

Pentazocine activates kappa receptors producing spinal analgesia and sedation while acting as a partial agonist or weak antagonist at mu receptors. This mixed profile gives it lower abuse potential than full mu agonists but can precipitate withdrawal in opioid-dependent patients and cause dysphoria from kappa activation. Option A is wrong because it is not a mu full agonist.

Reference: Katzung Basic and Clinical Pharmacology, 15th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.