Flumazenil

• intravenous – 1 – 2 minutes ⁴.

• intravenous – 6 – 10 minutes ⁴.

Flumazenil antagonises the CNSthe Central Nervous System, upon which certain drugs act effects produced by benzodiazepines, but does not antagonise the central nervous systembrain and spinal cord effects of drugs affecting GABA-ergic neurons by means other than the benzodiazepine receptor (including ethanol, barbiturates, or general anaesthetics) and does not reverse the effects of opioids ².

Hepatic. Flumazenil is completely (99%) metabolised. The major metabolites of flumazenil identified in urine are the de-ethylated free acid and its glucuronide conjugate ².

Initial distribution half-lifethe amount of time required for the amount of something to fall to half its initial value is 4 to 11 minutes and the terminal half-lifethe amount of time required for the amount of something to fall to half its initial value is 40 to 80 minutes. Prolongation of the half-lifethe amount of time required for the amount of something to fall to half its initial value to 1.3 hours in patients with moderate hepatic impairment and 2.4 hours in severely impaired patients ².

Flumazenil is completely (99%) metabolised. Elimination of radiolabeled drug is essentially complete within 72 hours, with 90% to 95% of the radioactivity appearing in urine and 5% to 10% in the faeces ².

LD50the amount of a material, given all at once, which causes the death of 50% (one half) of a group of test animals. The LD50 is one way to measure the short-term poisoning potential (acute toxicity) of a material in rats 1.8903 mol/kg ².

Flumazenil, an imidazobenzodiazepine derivative, antagonises the actions of benzodiazepines on the central nervous systembrain and spinal cord. Flumazenil competitively inhibits the activity at the benzodiazepine recognition site on the GABAGamma-aminobutyric acid (GABA) is an inhibitory neurotransmitter in your brain, meaning it slows your brain's functions. GABA is known for producing a calming effect./benzodiazepine receptor complex. Flumazenil is a weak partial agonist in some animal models of activity, but has little or no agonist activity in man ².

• Avoid in patients with chronic use (risks of severe withdrawal including Seizuresthe outward effect can vary from uncontrolled jerking movement (tonic-clonic seizure) to as subtle as a momentary loss of awareness More),
  • Most toxicology guidelines do not recommend Flumazenil in Overdose,
  • Potential harms appear to outweigh benefits in most cases,
  • See also ‘Adverse Events Associated with Flumazenil Treatment’ ⁵.
• May cause acute withdrawal if physically dependent.
• Do not give routinely to comatose patients,
  • Only use if identity of drug is known, and certain that the patient has not used chronically.
• Reverses Seizure protection of Benzodiazepines,
  • Increases risk of drugs that lower Seizure threshold (Cocaine, Tricyclic Antidepressants) ⁴.

Call your doctor at once if you have any of these serious side-effects –

• seizuresthe outward effect can vary from uncontrolled jerking movement (tonic-clonic seizure) to as subtle as a momentary loss of awareness More (convulsionswhen your body shakes violently without you meaning it to),
• weak or shallow breathing,
• continued drowsiness for longer than 2 hours after receiving flumazenil,
• confusiontrouble focusing, slow or disorganised thinking, poor short-term memory, unsure of time or place, or having difficulty following a conversation,
• fear,
• panic attack,
• fast or uneven heart rate ⁶.

• tremors,
• warmth, redness, or tingly feeling under your skin,
• dizziness,
• sweating or shivering,
• headache,
• blurred vision,
• tinnitus ⁶.