Which antidote is used for benzodiazepine overdose?

• A. Naloxone
• B. Flumazenil
• C. Physostigmine
• D. Haloperidol

Answer: (B)

Flumazenil is used to reverse benzodiazepine overdose. Benzodiazepines enhance GABA’s inhibitory effect at the GABA-A receptor, producing sedation and, in overdose, potentially dangerous respiratory depression. Flumazenil acts as a competitive antagonist at the benzodiazepine binding site on the GABA-A receptor, displacing the drug and rapidly restoring normal GABAergic inhibition. That makes it the appropriate antidote for this toxidrome.

Naloxone reverses opioid toxicity by blocking mu receptors; physostigmine counteracts anticholinergic toxicity by increasing acetylcholine; haloperidol is an antipsychotic with no role as an antidote for overdose. A caveat: reversing benzodiazepines with flumazenil can precipitate seizures or withdrawal in patients who are benzodiazepine-dependent or have co-ingested seizure-causing substances, so use is selective and judicious.