ZOVIRAKS

INSTRUCTIONS for medical use of the medicinal product FLUMAZENIL-VISTA (FLUMAZENIL-VISTA)

Composition

active substance: flumazenil; 1 ml of solution contains 0.1 mg of flumazenil; excipients: sodium chloride, disodium edetate, glacial acetic acid, sodium hydroxide, water for injections.

Pharmaceutical form

Solution for injection.

Main physical and chemical properties

Transparent, colorless solution.

Pharmacotherapeutic group

Other therapeutic agents. Antidotes. ATC code V03AB25.

Pharmacological properties

Pharmacodynamics

Mechanism of action

Flumazenil is a benzodiazepine antagonist, an imidazobenzodiazepine derivative that, through competitive interaction, specifically blocks the effects of substances acting on the benzodiazepine receptor in the central nervous system (CNS). There have been reports of neutralization of paradoxical benzodiazepine reactions.

Pharmacodynamic effects

Experiments conducted on animals have shown that flumazenil does not block the effects of benzodiazepine receptor agonists, such as barbiturates, mimetics of gamma-aminobutyric acid, and adenosine receptor antagonists. Flumazenil blocks the action of non-benzodiazepine agonists, such as cyclopyrrolones (zoplicone) and triazolopyridazines. The hypnotic-sedative effects of benzodiazepines quickly disappear (within 1-2 minutes) after intravenous administration of flumazenil. Depending on the difference in elimination time between the agonist and antagonist, the effect may recur within several hours. Flumazenil may have slight agonistic (e.g., anticonvulsant) activity. Clinical efficacy and safety. Animal studies have shown that with prolonged treatment with flumazenil, a withdrawal syndrome developed, including seizures.

Pharmacokinetics

Distribution

Flumazenil is a weakly lipophilic base. Flumazenil is bound to approximately 50% of plasma proteins, of which 2/3 are bound to albumin. Flumazenil is intensely distributed in the extracellular space. During the distribution phase, the concentration of flumazenil in plasma decreases with a half-life of 4-5 minutes. The volume of distribution at steady-state concentration is 0.9-1.1 L/kg.

Metabolism

Flumazenil undergoes intensive metabolism in the liver. The most important inactive metabolite in plasma (in free form) and urine (in free and conjugated form) is carboxylic acid. The results of pharmacological tests have shown that this metabolite does not have agonistic or antagonistic benzodiazepine activity.

Elimination

Flumazenil is almost completely excreted in the urine. This indicates complete breakdown of the active substance in the body. Studies with a radiolabeled drug have shown that complete excretion occurs within 72 hours: 90-95% with urine and 5-10% with feces. Elimination is rapid, as evidenced by a short half-life (40-80 minutes). The total clearance of flumazenil is 0.8-1.0 L/h/kg, and metabolism occurs mainly in the liver.

Clinical characteristics

Indications

The medicinal product is used to partially or completely eliminate the central sedative effects of benzodiazepines in adults and children over 1 year of age. It can be used in anesthesia and intensive care.

Contraindications

• Increased sensitivity to the active substance or to any of the components of the medicinal product.
• Treatment of potentially life-threatening conditions with benzodiazepines (e.g., control of intracranial pressure or epileptic status).
• Severe intoxication caused by cyclic antidepressants (seizures, focal seizures, QRS prolongation, arrhythmia, mydriasis, anticholinergic symptoms).

Interaction with other medicinal products and other types of interactions

Interaction studies were conducted only in adult patients. Flumazenil suppresses the central effects of benzodiazepines by competitive inhibition at the receptor level. It also blocks the action of non-benzodiazepine agonists (e.g., zoplicone, triazolopyridazines) on benzodiazepine receptors. However, flumazenil does not block the action of medicinal products that do not work through this mechanism. No interaction with other CNS depressants has been observed.

Special instructions

Monitoring

When using flumazenil to eliminate sedation caused by benzodiazepines, it is necessary to monitor the dose, vital signs (electrocardiogram (ECG)), pulse, oximetry, concentration of the patient's attention, and other vital signs (such as heart rate, respiratory rate, and blood pressure) for a long time, as well as the duration of the effect of the used benzodiazepine for the occurrence of symptoms of repeated sedation, difficulty breathing, or other signs of residual benzodiazepine effect.

Anxiety

It is necessary to carefully select the dosage of flumazenil for patients who suffer from preoperative anxiety or have a history of chronic or episodic anxiety.

Postoperative pain

Postoperative pain should be taken into account. It may be better to keep the patient sedated.

Pediatric use

Due to the likelihood of repeated sedation and difficulty breathing in children who have been sedated with midazolam, it is necessary to carefully monitor them for at least 2 hours after administration of flumazenil.

Overdose

Symptoms. Even when used in higher doses than recommended (up to 100 mg of flumazenil), symptoms of overdose have not been observed.

Adverse reactions

Shelf life

3 years.

Storage conditions

No special storage conditions are required for the medicinal product. Store in a place inaccessible to children.

Packaging

5 ml in an ampoule; 5 or 10 ampoules in a cardboard pack.

Release category

By prescription.

Manufacturer

LABORATORIO REIG JOFRÉ, S.A.

Location of the manufacturer and its business address

C/Gran Capitán, 10, Sant Joan Despí, Barcelona, 08970, Spain