Article Text

Download PDFPDF

Flumazenil and suspected benzodiazepine overdose
  1. Pranay Kumar Singh,
  2. Katrina Richell-Herren
  1. Department of Emergency Medicine, Manchester Royal Infirmary, Oxford Road, Manchester M13 9WL

    Statistics from

    Request Permissions

    If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.

    Report by Pranay Kumar Singh, Medical Student Search checked by Katrina Richell-Herren, Research Fellow

    Clinical scenario

    An unresponsive young adult is brought to the emergency department. No history is available. Neurological examination reveals no focal abnormality and pupils are mid-size and reactive. Blood glucose is normal. You suspect an overdose and wonder whether flumazenil should be given to ascertain whether benzodiazepines are involved.

    Three part question

    In [patients with suspected overdose] is [a single dose of flumazenil] indicated to [safely diagnose benzodiazepine ingestion]?

    Search strategy

    Medline 1966–01/00 using the OVID interface. [({exp flumazenil OR} AND {exp overdoses OR OR exp poisoning OR}) AND {exp diagnosis OR exp diagnosis, differential OR OR diagnos$.mp}] LIMIT to human AND english.

    Search outcome

    Altogether 45 papers were found of which 39 were irrelevant or of insufficient quality.The remaining six papers are shown in table 3.

    Table 3


    All the studies are small. Most are PRCTs investigating the use of flumazenil in the management of benzodiazepine overdose. These show that flumazenil improves conscious levels in patients who have taken overdoses. Significant adverse reactions occurred including fitting and transient increases in conscious level. Only the diagnostic study gives some idea of the clinical utility of the test.

    Clinical bottom line

    The sensitivity of a single dose of flumazenil is high enough to allow failure to respond to be used as a SnNout for benzodiazepine overdose. The specificity is too low to allow it to be used to rule-in. The possibility of mixed overdose is a relative contraindication to using flumazenil.

    Report by Pranay Kumar Singh, Medical Student Search checked by Katrina Richell-Herren, Research Fellow