Flumazenil is used to reverse which category of substances?

• A. Opioids
• B. Alcohol
• C. Cannabis
• D. Benzos

Answer: (D)

Flumazenil acts as a competitive antagonist at the benzodiazepine binding site on the GABA-A receptor, so it blocks the CNS depressant effects of benzodiazepines and rapidly reverses sedation and respiratory depression caused by benzodiazepine overdose. This makes it the reversal agent of choice for benzodiazepines, not for opioids, alcohol, or cannabis. In practice, reversal is not without risk: in people who are benzodiazepine dependent, it can precipitate withdrawal and seizures, and long-acting benzodiazepines may outlast flumazenil, causing re-sedation. Dosing is typically a small IV dose (for example 0.2 mg) given over a few seconds and repeated every minute with small increments up to about 1 mg per protocol, with close monitoring.