Flumazenil (Rx: Romazicon) has recently been described as coming into favor for two unique purposes: (1) hepatic encephalopathy and (2) paradoxical reactions to benzodiazepines.

Regarding the first, flumazenil’s use in hepatic encephalopathy has been well described recently in a Cochrane review of 113 RCTs with a total n = 805, wherein flumazenil had a significant beneficial effect on short term improvement of hepatic encephalopathy.¹ This is thought to occur physiologically secondary to reversal of the origin of hepatic encephalopathy—i.e., an accumulation of substances that bind to a receptor-complex in the brain resulting in neural inhibition¹ (principally GABA receptors which are forefront in the stimulation of sedation). Therefore GABA receptor antagonists (such as flumazenil) can be used to directly oppose this mechanism. Effect on full recovery and survival has still not been proven with flumazenil administration.¹

Secondly, flumazenil can be used for paradoxical reactions to benzodiazepines^2,4 and in a 10 year review of its use, published in the Journal of Emergency Medicine,³ the real safety of this drug has once again come into question, as there were relatively few adverse outcomes even in the highest of seizure provocation risk—which occurred with co administration of pro-convulsant (e.g., TCAs) at a 2.7 % incidence (8/293)—the total incidence including all subjects bore a rate of 1.4% of seizure activity (n = 904).³

I present an example of administration in the second of indications above. I took care of a 26 yo WF with PMH of asthma, a prior severe dental cavity pending root canal and an IV heroin addiction, currently sober and progressing through the the 12 Steps program at the Healing Place. She presented in sepsis, afebrile with qSOFA of 0/3 (Labs: WBC 21.2 with left shift, procal 1.33, ESR 83, CRP 201, lactic acid 0.8 s/p 2 L NS IVFs), and AKI (Cr. 1.6) with dental as well as urinary possible sources. She was eventually discharged on day 3 with Dx of urosepsis, creatinine returned to normal, and had a negative echo for routine endocarditis rule out in the setting of PMH of IVDA.

During her ER stay she was uncomfortable, diaphoretic, pale, GCS of 15, but anxious and in pain, professing severe insomnia for 3 days, stating, “I just want to sleep”. A trial of oral Ativan 2 mg was given, as she did not want any pain medication due to her prior addiction. She noted a small temporary improvement; however 2 hours later this beneficial effect was absent. By now she had received cefepime 2g and vancomycin 25 mg/kg (for potential osteomyelitis coverage), and was requesting more anxiety medications, having already received 50 mg IV Benadryl 30 minutes prior with no improvement noted. Clinically she was GCS 15, pleasant in interaction, increasingly pale, uncomfortable, wide awake at 0445, and subjectively in pain. She was then given 2 mg IV Versed.

Immediately following the administration of midazolam she became altered to GCS 12 (E4, V3, M5), eyes wide, extremities tremulous, pulled out all of her IVs, and was trying to jump off the bed. It was clear she was paradoxically agitated and hyper-aroused. Rather than reversing her (though we doubted history of benzodiazepine use), we opted to watch and see if this reaction would subside without intervention since she responded favorably to the oral Ativan; however the rarely seen but well known paradoxical reaction to Versed was suspected. She was observed 1:1 and thereafter 3:1 for 40 minutes, at which time she appeared to be steadily worsening rather than improving. The decision was made to give an IV push of 0.2 mg of flumazenil (Rx: Romazicon). Within 30 seconds after administration she once again returned to her pleasant self, she was GCS 15, appropriate, and had no recollection of the previous hour, and had no seizure activity noted throughout her stay. She maintained a healthy mental status of GCS 15 and was AAOx4 for the rest of her evaluation and admission.

In 2010, Kreshak et al. reported a similar case and treatment. This paradoxical reaction to Versed in their report is thought to occur at less than 1% incidence, however it is described as commonly as 1.4 %.⁴ In the reported literature this reaction is described as a patient becoming acutely agitated, restless and aggressive². Stiffening and jerking of the extremities, and shaking of a part of the body are also noted. When observing a patient with this reaction, after ruling out other etiologies of agitated AMS, Kreshak et al. (2010) opted to administer flumazenil 0.5mg IV, and “…immediately after which the patient became conscious, oriented and calm, the paradoxical reaction was terminated”. The patient had no recollection of the events,² similar to the patient observed in the ULED.

Per Kreshak et al. (2010), there exist “…different theories concerning the mechanism of paradoxical reactions, involving a central cholinergic effect or the serotonin imbalance”.² Unfortunately the exact mechanism of paradoxical reactions remains unclear.

Although difficult to locate literature, if seizures develop following flumazenil administration, pharmacology guidelines recommend Valium 20-30 mg IV then immediately switching to barbiturates; some soft EM sources also suggest going straight to propofol.⁵

Thank you for reading my post.

References

1. Als-Nielsen, B., Kjaergard, L., & Gluud, C. (2001). Benzodiazepine receptor antagonists for acute and chronic hepatic encephalopathy. The Cochrane Database of Systematic Reviews (Complete Reviews). doi:10.1002/14651858.cd002798
2. Cabrera, L., Santana, A., Robaina, P., & Palacios, M. (2010). Paradoxical reaction to midazolam reversed with flumazenil. Journal of Emergencies, Trauma, and Shock J Emerg Trauma Shock, 3(3), 307. doi:10.4103/0974-2700.66551
3. Kreshak, A. A., Cantrell, F. L., Clark, R. F., & Tomaszewski, C. A. (2012). A Poison Center’s Ten-year Experience with Flumazenil Administration to Acutely Poisoned Adults. The Journal of Emergency Medicine, 43(4), 677-682. doi:10.1016/j.jemermed.2012.01.059
4. Tae, C. H., Kang, K. J., Min, B., Ahn, J. H., Kim, S., Lee, J. H., . . . Kim, J. J. (2014). Paradoxical reaction to midazolam in patients undergoing endoscopy under sedation: Incidence, risk factors and the effect of flumazenil. Digestive and Liver Disease, 46(8), 710-715. doi:10.1016/j.dld.2014.04.007
5. (n.d.). Retrieved August 23, 2016, from http://www.goodfriendem.com/2013/05/flumazenil-romazicon-is-probably-safer.html