Particular caution is necessary when using Flumazenil in cases of mixed-substance overdose since the toxic effects (such as convulsions and cardiac dysrhythmias) of other medicines taken in overdose (especially cyclic antidepressants) may emerge with the reversal of benzodiazepine effects by Flumazenil.
The use of Flumazenil is not recommended in epileptic patients who have been receiving benzodiazepine treatment for a prolonged period. Although Flumazenil exerts a slight intrinsic anticonvulsant effect, its abrupt suppression of the protective effect of a benzodiazepine agonist can give rise to convulsions in epileptic patients.
Patients who have received Flumazenil for the reversal of benzodiazepine effects should be monitored for resedation, respiratory depression, or other residual benzodiazepine effects for an appropriate period based on the dose and duration of effect of the benzodiazepine employed. As patients with underlying hepatic impairment may experience delayed benzodiazepine effects, an extended observation period may be required.
When Flumazenil is used with neuromuscular-blocking agents, it should not be injected until the effects of neuromuscular blockade have been fully reversed.
Flumazenil should be used with caution in patients with head injury, as it may be capable of precipitating convulsions or altering cerebral blood flow in patients receiving benzodiazepines.
Rapid injection of Flumazenil should be avoided in patients with high-dose and/or long-term exposure to benzodiazepines ending at any time within the weeks preceding Flumazenil administration, as it may produce withdrawal symptoms, including agitation, anxiety, emotional lability, as well as mild confusion and sensory distortions.
Flumazenil is not recommended either as a treatment for benzodiazepine dependence or for the management of protracted benzodiazepine abstinence syndromes.
Flumazenil should be used with caution for the reversal of conscious sedation in children below the age of one year, for the management of overdose in children, for resuscitation of the newborn, and for reversal of the sedative effects of benzodiazepines used for induction of general anaesthesia in children, as experience is limited.