A chronic benzodiazepine user is brought to the emergency department with drowsiness after taking an unknown number of her alprazolam tablets. The resident considers giving flumazenil immediately. The main reason for caution is that flumazenil:

• A Has a shorter half-life than most benzodiazepines, allowing re-sedation
• B Can precipitate acute withdrawal and seizures in benzodiazepine-dependent patients ✓
• C Causes profound hypotension through alpha-2 receptor antagonism
• D Is ineffective unless given within 30 minutes of ingestion

Explanation

Flumazenil competitively antagonises the benzodiazepine site on the GABA-A receptor. In dependent patients it abruptly reverses tolerance effects and can trigger severe withdrawal with seizures, and in mixed overdoses with tricyclics it lowers the seizure threshold further. Hence it is reserved for selected cases, not routine reversal. Re-sedation due to its short half-life is real but the withdrawal-seizure hazard is the principal safety concern. It works whenever active benzodiazepine is present regardless of timing.

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.