A 35-year-old woman presents to the emergency department following deliberate ingestion of multiple diazepam tablets. She is drowsy but rousable, with a respiratory rate of 10/min. Which statement best describes the mechanism of action of the reversal agent used?

• A It opens GABA-gated chloride channels directly
• B It inhibits hepatic cytochrome P450 enzymes to slow diazepam metabolism
• C It activates glycine receptors to counter CNS depression
• D It competitively antagonises the benzodiazepine binding site on GABA-A receptors ✓

Explanation

Flumazenil is a competitive antagonist at the benzodiazepine modulatory site on GABA-A receptors; it displaces benzodiazepines without intrinsic agonist activity at therapeutic doses. Its short half-life (~1 hour) means re-sedation may occur with long-acting benzodiazepines, necessitating repeat dosing or infusion. It does not directly gate the chloride channel or alter drug metabolism.

Reference: KD Tripathi, Essentials of Medical Pharmacology, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.