A newly synthesized compound binds to the benzodiazepine site of the GABA-A receptor and, when given alone, produces effects opposite in direction to diazepam. In a receptor system engineered to show constitutive receptor activity, the compound reduces signaling below the baseline level. This compound is best classified as:

• A Competitive antagonist
• B Partial agonist
• C Irreversible antagonist
• D Inverse agonist ✓

Explanation

An inverse agonist stabilizes the inactive conformation of a receptor that shows constitutive (ligand-independent) activity, driving signaling below basal levels. Beta-carbolines at the benzodiazepine site are classic examples. A competitive neutral antagonist (option A) blocks agonists but leaves constitutive activity untouched, so it cannot reduce signaling below baseline. A partial agonist produces a positive response of intermediate magnitude, and irreversible antagonism describes bond chemistry, not direction of effect.

Reference: Goodman and Gilman's The Pharmacological Basis of Therapeutics, 14th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.