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Romazicon Side Effects

Generic name: flumazenil

Medically reviewed by Last updated on Jul 22, 2022.

Note: This document contains side effect information about flumazenil. Some dosage forms listed on this page may not apply to the brand name Romazicon.

Applies to flumazenil: parenteral injection.

Side effects include:

Dizziness, injection site pain, increased sweating, headache, and abnormal or blurred vision.

For Healthcare Professionals

Applies to flumazenil: intravenous solution.

Nervous system

Very common (10% or more): Dizziness (vertigo, ataxia) (10%)

Common (1% to 10%): Headache, paresthesia (sensation abnormal, hypoesthesia)

Frequency not reported: Convulsions, somnolence, speech disorder (dysphonia, thick tongue)[Ref]

Convulsions have occurred in patients with severe hepatic impairment, inpatients relying on benzodiazepine effects to control seizures, patients physically dependent on benzodiazepines, and those who have ingested large doses of other drugs (mixed-drug overdose).[Ref]


Common (1% to 10%): Agitation (anxiety, nervousness, dry mouth, tremor, palpitations, insomnia, dyspnea, hyperventilation), emotional lability (crying abnormal, depersonalization, euphoria, increased tears, depression, dysphoria, paranoia)

Frequency not reported: Confusion (difficulty concentrating, delirium)

Postmarketing reports: Fear, panic attacks in patients with a history of panic disorders[Ref]


Common (1% to 10%): Cutaneous vasodilation (sweating, flushing, hot flushes)

Uncommon (0.1% to 1%): Cardiac dysrhythmias (ventricular tachycardia, junctional tachycardia)

Frequency not reported: Arrhythmia (atrial, nodal, ventricular extrasystoles), bradycardia, tachycardia, hypertension, chest pain[Ref]


The majority of deaths occurred in patients with serious underlying disease or in patients who had injects large amounts of non-benzodiazepine drugs (usually cyclic antidepressants) as part of an overdose.

Withdrawal symptoms may occur after rapid injection of flumazenil (the active ingredient contained in Romazicon) in patients with long term exposure to benzodiazepines.[Ref]

Common (1% to 10%): Fatigue (asthenia, malaise)

Frequency not reported: Death, abnormal hearing (transient hearing impairment, hyperacusis, tinnitus), rigors, shivering

Postmarketing reports: Withdrawal symptoms[Ref]


Common (1% to 10%): Injection site pain, injection site reaction (thrombophlebitis, skin abnormality, rash)[Ref]


Common (1% to 10%): Abnormal vision (visual field defect, diplopia)[Ref]


Frequency not reported: Hiccup[Ref]


1. LaFleche FR, Milzman DP "Flumazenil & coma." Ann Emerg Med 20 (1991): 1397

2. Lheureux P, Vrankx M, Askenasi R "Administration of flumazenil." Ann Emerg Med 20 (1991): 592-3

3. Marchant B, Wray R, Leach A, Nama M "Flumazenil causing convulsions and ventricular tachycardia." BMJ 299 (1989): 860

4. Mordel A, Winkler E, Almog S, Tirosh M, Ezra D "Seizures after flumazenil administration in a case of combined benzodiazepine and tricyclic antidepressant overdose." Crit Care Med 20 (1992): 1733-4

5. Thomas P, Lebrun C, Chatel M "De novo absence status epilepticus as a benzodiazepine withdrawal syndrome." Epilepsia 34 (1993): 355-8

6. "Flumazenil." Med Lett Drugs Ther 34 (1992): 66-8

7. Short TG, Galletly DC "Residual psychomotor effects following reversal of midazolam sedation with flumazenil." Anaesth Intensive Care 17 (1989): 290-7

8. "Product Information. Romazicon (flumazenil)." Roche Laboratories (2001):

9. Chern TL, Kwan A "Flumazenil-induced seizure accompanying benzodiazepine and baclofen intoxication." Am J Emerg Med 14 (1996): 231-2

10. "Product Information. Flumazenil (flumazenil)." Baxter I.V. Systems Division (2018):

11. Seebach J, Jost R "Flumazenil-induced psychotic disorder in hepatic encephalopathy." Lancet 339 (1992): 488-9

12. Griffiths RR, Evans SM, Guarino JJ, Roache JD, Furman WR, Liebson I, Schwam EM "Intravenous flumazenil following acute and repeated exposure to lorazepam in healthy volunteers: antagonism and precipitated withdrawal." J Pharmacol Exp Ther 265 (1993): 1163-74

13. Birch BR "Cardiac arrest associated with flumazenil." BMJ 305 (1992): 180-1

14. Katz Y, Boulos M, Singer P, Rosenberg B "Cardiac arrest associated with flumazenil." BMJ 304 (1992): 1415

15. Bodenham AR "Death after flumazenil." BMJ 299 (1989): 457

16. Short TG, Maling T, Galletly DC "Ventricular arrhythmia precipitated by flumazenil." Br Med J (Clin Res Ed) 296 (1988): 1070-1

17. Herd B, Clarke F "Complete heart block after flumazenil." Hum Exp Toxicol 10 (1991): 289

18. Lopez A, Rebollo J "Benzodiazepine withdrawal syndrome after a benzodiazepine antagonist." Crit Care Med 18 (1990): 1480-1

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.