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    Flumazenil molecular structure

    Flumazenil Stats & Data

    Anexate Lanexat Mazicon Romazicon Ro 15-1788
    NPS DataHub
    MW303.29
    FormulaC15H14FN3O3
    CAS78755-81-4
    IUPACethyl 8-fluoro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylate
    SMILESCCOC(=O)c1ncn2c3ccc(F)cc3C(=O)N(C)Cc12
    InChIKeyOFBIFZUFASYYRE-UHFFFAOYSA-N
    Chemical Class Benzodiazepine
    Psychoactive Class Depressant

    Pharmacology

    DrugBank
    State Solid Vd * 0.9 to 1.1 L/kg

    Description

    Fumazenil is an imidazobenzodiazepine derivative and a potent benzodiazepine receptor antagonist that competitively inhibits the activity at the benzodiazepine recognition site on the GABA/benzodiazepine receptor complex, thereby reversing the effects of benzodiazepine on the central nervous system.

    Mechanism of Action

    Flumazenil, an imidazobenzodiazepine derivative, is a benzodiazepine antagonist. It competitively inhibits the benzodiazepine binding site on the GABA/benzodiazepine receptor complex. Flumazenil is a weak partial agonist in some animal models of activity, but has little or no agonist activity in man.

    Pharmacodynamics

    Flumazenil antagonizes the CNS effects produced by benzodiazepines, but does not antagonize the central nervous system effects of drugs affecting GABA-ergic neurons by means other than the benzodiazepine receptor (including ethanol, barbiturates, or general anesthetics) and does not reverse the effects of opioids.

    Metabolism

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

    Toxicity

    In clinical studies, most adverse reactions to flumazenil were an extension of the pharmacologic effects of the drug in reversing benzodiazepine effects.

    Indication

    For the complete or partial reversal of the sedative effects of benzodiazepines in cases where general anesthesia has been induced and/or maintained with benzodiazepines, and where sedation has been produced with benzodiazepines for diagnostic and therapeutic procedures. Also for the management of benzodiazepine overdose as an adjunct for appropriate supportive and symptomatic measures.

    Half-life

    Initial distribution half-life is 4 to 11 minutes and the terminal half-life is 40 to 80 minutes. Prolongation of the half-life to 1.3 hours in patients with moderate hepatic impairment and 2.4 hours in severely impaired patients. Compared to adults, the elimination half-life in pediatric patients was more variable, averaging 40 minutes (range: 20 to 75 minutes).

    Protein Binding

    Protein binding is approximately 50%, mostly (66%) to albumin. Protein binding is reduced in patients with hepatic cirrhosis.

    Elimination

    Flumazenil is completely (99%) metabolized. 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 feces.

    Clearance

    * 1 L/hr/kg healthy volunteers receiving a 5-minute infusion of a total of 1 mg

    Effect Profile

    Curated
    Benzodiazepine 3.6

    Low anxiolysis and sedation

    Anxiolysis×3
    3
    Sedation / Relaxation×2
    3
    Motor / Cognitive Impairment×1
    0
    Euphoria / Mood Lift×1
    0

    Tolerance & Pharmacokinetics

    drugs.wiki

    Tolerance Decay

    Full tolerance 3d Half tolerance 37d Baseline ~60d
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