Details About Overdose or Poisoning Generic Salt :: Flumazenil
Drug Pharmacology ::
I. Pharmacology. Flumazenil(Romazicon) is a highly selective competitive inhibitor of CNSbenzodiazepine receptors. It has no demonstrable benzodiazepine agonistactivity and no significant toxicity even in high doses. It has noeffect on alcohol or opioid receptors, and it does not reverse alcoholintoxication. Flumazenil is most effective parenterally (highfirst-pass effect with oral administration). After intravenousadministration, the onset of benzodiazepine reversal occurs within 1–2minutes, peaks at 6–10 minutes, and lasts for 1–5 hours, depending onthe dose of flumazenil and the degree of preexisting benzodiazepineeffect. It is eliminated by hepatic metabolism, with a serum half-lifeof approximately 1 hour.
Drug Indications ::
Rapidreversal of benzodiazepine overdose–induced coma and respiratorydepression, both as a diagnostic aid and as a potential substitute forendotracheal intubation. Rule out high-risk patients (see below).Lowest-risk patients include patients with a known iatrogenic exposure,toddler ingestion, and patients with a paradoxic response(characterized by agitation or excitement and excessive movement orrestlessness) to a benzodiazepine where reversal of effect is desired.
Postoperative or postprocedure reversal of benzodiazepine sedation.
Flumazenilmay reverse CNS depression from certain non–benzodiazepine sedativesand hypnotics, eg, zolpidem (Ambien) and zaleplon (Sonata).
Drug Contra-Indications ::
Known hypersensitivity to flumazenil or benzodiazepines.
Suspected serious tricyclic antidepressant or other proconvulsant overdose.
Benzodiazepineuse for control of a potentially life-threatening condition (eg, statusepilepticus or increased intracranial pressure).
Drug Adverse Effects ::
IV. Adverse effects
Anxiety, agitation, headache, dizziness, nausea, vomiting, tremor, and transient facial flushing.
Rapidreversal of benzodiazepine effect in patients with benzodiazepineaddiction or high tolerance may result in an acute withdrawal state,including hyperexcitability, tachycardia, and seizures (rarelyreported).
Seizures or arrhythmias may be precipitated in patients with a serious cyclic antidepressant or other proconvulsant overdose.
Flumazenil has precipitated arrhythmias in a patient with a mixed benzodiazepine and chloral hydrate overdose.
E. Other risks include resedation and aspiration.
F. Use in pregnancy. FDAcategory C (indeterminate). This does not preclude its acute,short-term use for a seriously symptomatic patient (see Table III–1).
Drug Lab Interactions ::
Drug or laboratory interactions. No known interactions. Flumazenil does not appear to alter the kinetics of benzodiazepines or other drugs.
Drug Dose Management ::
Dosage and method of administration
Benzodiazepine overdose. Titrate the dosage until the desired response is achieved.
1. Administer0.2 mg IV over 30 seconds (pediatric dose not established; start with0.01 mg/kg). If there is no response, give 0.3 mg. If there still is noresponse, give 0.5 mg and repeat every 30 seconds if needed to a totalmaximum dose of 3 mg (1 mg in children).
2. Becauseeffects last only 1–5 hours, continue to monitor the patient closelyfor resedation. If multiple repeated doses are needed, consider acontinuous infusion (0.2–1 mg/h).
Reversal of conscious sedation or anesthetic doses of benzodiazepine. A dose of 0.2 mg given intravenously is usually sufficient and may be repeated, titrating up to 1 mg.
Drug Chemical Formulations ::
Parenteral. Flumazenil (Romazicon), 0.1 mg/mL, 5- and 10-mL vials with parabens and EDTA.
The suggested minimum stocking level to treat a 70-kg adult for the first 24 hours is 10 vials (0.1 mg/mL, 10 mL).