Regarding, flumazenil, true is: (AIIMS Nov 2009)
|A||It is a specific antagonist of benzodiazepine receptors|
|B||It Acts on both barbiturate & benzodiazepine receptors|
|C||Long acting and can be used in phenobarbitone poisoning|
|D||Does not undergo redistribution|
a. Benzodiazepine overdose is common and is characterized by ataxia, in coordination, slurring speech, coma and respiratory depression.
b. Flumazenil, an imidazobenzodiazepine derivative is a specific antidote of benzodiazepine receptors (BZDs) and is a short acting drug.
c. It undergoes quick redistribution.
d. That is why, repeated dosing may be necessary. This is because, many benzodiazepines have much longer half lives than flumazenil.
e. Since it is specific antidote, therefore, the drug has no value in poisoning by other CNS depressants. The drug is also useful in hepatic coma.
f. It has been in clinical use for last 20 years and it could be used both for diagnostic or therapeutic purposes.
g. Since, it blocks BZDs receptors; it is the drug of choice for BZD overdose.
h. The drug is also useful in zaleplone or zolpidem poisoning.
i. The effect of drug is rapid and is seen with in 2-3 minutes. Starting dose is 200 microgram every 1-2 minutes and maximum dose is 3 mg/hour.
j. It is noteworthy that the drug should not routinely be used in patients with decreased level of consciousness in patients with poisoning by other CNS depressants. Seizures can occur if this is done.