A kappa-opioid receptor agonist produces analgesia but also causes significant dysphoria and hallucinations. Which statement about kappa receptor activation is correct?

• A Kappa activation produces euphoria similar to mu receptor activation
• B Kappa activation causes respiratory depression greater than mu activation
• C Kappa activation produces dysphoria, miosis, and spinal analgesia ✓
• D Kappa activation causes significant physical dependence greater than mu activation

Explanation

Kappa receptor activation produces spinal analgesia and miosis but notably causes dysphoria and sedation rather than euphoria. This contrasts with mu activation which produces euphoria. Respiratory depression and physical dependence are predominantly mu-mediated. The dysphoric property of kappa agonists limits their clinical use despite analgesic efficacy.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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