Numerous media have reported on the growing use and abuse of psychotropic drugs in our society . Benzodiazepines are among the most widely used drugs for dealing with anxiety disorders, playing a supportive role in many psychological treatments.

However, all that glitters is not gold: it has been documented that benzodiazepines can lead to physical and psychological dependence (including overdose), excessive sleepiness and even depressive symptoms, interfering with the user’s daily life.

Flumazenil, the protagonist of this article , is the drug responsible for combating drowsiness produced by benzodiazepines in very specific situations.

What is Flumazenil?

Flumazenil (brand names: Anexate, Lanexat, Mazicon, Romazicon) is a medicine that works as a GABA antagonist . It blocks, by competitive inhibition, the effects produced by benzodiazepines in our Central Nervous System. At the moment it is the only benzodiazepine receptor antagonist available on the pharmaceutical market.

Two basic properties are attributed to this drug, as we shall see. On the one hand, reverses the sedation produced by benzodiazepines . On the other hand, it helps to reduce psychomotor slowness.

Uses of Flumazenil

Flumazenil is used in adults to correct the sedative effects of benzodiazepines. It can be used in two main situations: anesthesia and palliative care .

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In anaesthesia, it is used to end the hypnosedative effects resulting from general anaesthesia maintained or induced in hospitalised patients. It is also used for the reduction and correction of benzodiazepine sedation for diagnostic or therapeutic procedures in outpatient or hospital settings.

In intensive care, the aim is to restore the patient’s spontaneous breathing , correcting the central effects of benzodiazepines. In addition, it is also used for the diagnosis and treatment of overdose or intoxication resulting from benzodiazepine abuse.

Apart from these uses, there is evidence that flumazenil may be effective in treating prolonged benzodiazepine withdrawal , with fairly promising results, as well as reducing benzodiazepine tolerance, although more studies are needed.

In addition, it has been used to treat hepatic encephalopathy, although in this case the results have been contradictory and not as promising.

Its use is not suitable for the paediatric population, only for children over 1 year of age.

Form of administration and dose

This medicine can only be administered intravenously, so can only be applied by a healthcare professional . Flumazenil can be administered as an injection or infusion, and can be used in parallel with other resuscitation techniques.

As far as dosage is concerned, we will only focus on the adult population. In cases where the person has been anesthetized, the recommended dose is 0.2 milligrams, administered intravenously, for approximately 15 seconds. In cases where the required degree of consciousness has not been achieved, an additional dose of 0.1mg may be injected. In general terms, the usual dose required in these cases fluctuates between 0.3-0.6mg .

The dose is different in intensive care. Starting with a dose of 0.3mg intravenously , if the required degree of consciousness is not obtained within 60 seconds , a dose of 0.1mg may be applied, up to a maximum dose of 2.0mg.

It may be that the person did not regain the desired degree of consciousness and that his or her breathing was not stable after the administration of the doses. In these cases, consideration should be given to the fact that the intoxication may not be caused by the consumption of benzodiazepines.

Side effects

As is the case with the vast majority of medicines on the market, a series of adverse reactions can occur, which we will detail below. However, many of the adverse reactions tend to disappear quickly or progressively without the need for special intervention.

Very frequent

  • Insomnia.
  • Sleepiness.
  • Vertigo and headaches.
  • Dry mouth and tremors .
  • Hyperventilation.
  • Seizures.

Frequent

Hypotension.
Nausea and vomiting .
Sweating.
Fatigue.
Pain at the injection site.

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Rare

  • Anxiety and fear .
  • Panic attacks in patients with a history of panic attacks.
  • Abnormal hearing.
  • Palpitations .
  • Tachycardia or bradycardia.
  • Cough and nasal congestion .

Warnings and Cautions

Before using flumazenil, a number of precautions should be taken.

Flumazenil has a shorter effect than benzodiazepines, so it is recommended that the patient be monitored in the intensive care unit until the effect of flumazenil is assumed to have worn off.

The use of flumazenil is not always the best option. For example, in patients with heart problems , it is not always a good alternative for the patient to wake up quickly from anesthesia. In these cases it may be preferable to maintain a certain degree of sedation.

After major surgery, it is important to note that the patient will be in pain during the post-operative period. Therefore, it may be preferable to keep the patient slightly sedated.

Special consideration should be given to the dosage of flumazenil in people with preoperative anxiety or those with a history of anxiety disorders.

The use of flumazenil is not recommended in patients with epilepsy who have been treated with benzodiazepines in the past for a prolonged period.

For persons treated for long periods with high doses of benzodiazepines, the advantages of using flumazenil should be carefully assessed against the risk of triggering withdrawal symptoms.

Flumazenil should be used with caution in patients suffering from alcoholism , due to increased tolerance and dependence on benzodiazepines in this population.

Contraindications

When should flumazenil not be administered? Its use is not recommended in patients with known hypersensitivity to flumazenil or benzodiazepines. According to experts, it should also not be used in patients who have been given a benzodiazepine to control a life-threatening condition (eg, endocranial pressure).