Flumazenil is (DNB Dec 2012)
|A||Agonist of diazepam|
a. Antagonism– When one drug decreases or inhibits the action of another, they are antagonistic. Usually in an antagonistic pain, one drug is inactive as such but decreases the effect of the other.
b. Flumazenil, an imidazobenzodiazepine, is a specific and competitive antagonist of benzodiazepines at benzodiazepine receptors.
c. Flumazenil– It is a BZD analogue, which has little intrinsic activity (practically no effect on normal subjects), but competes with BZD receptor and reverses their depressant or stimulant effects respectively.
d. It abolishes the hypnogenic, psychomotor, cognitive and EEG effects of BZDs. At higher doses it has some week BZD agonist like as well as an inverse agonist like activity, but these are of no clinical significance.
e. On IV injection, action of flumazenil starts in seconds and lasts for
- 1–2 hr; elimination t1/2 is 1 hr, due to rapid metabolism.
a. To reverse BZD anesthesia
i. It allows early discharge of patients after diagnostic procedures and facilitates post-anesthetic management.
b. BZD overdose
i. Majority of patients of BZD overdose require only supportive measures like patent airway, maintenance of BP, cardiac and renal function, etc. In addition, flumazenil 0.2 mg/min may be injected
IV till the patient regains consciousness.
• Flumazenil is safe and well tolerated. Agitation, discomfort, tearfulness, anxiety, coldness and withdrawal seizures are the occasional side effects.