Reversal Agents

Flumazenil

Flumazenil is a short-acting agent that reverses benzodiazepine-induced sedation. Re-sedation may occur due to its short duration of action, therefore additional doses may be necessary. Flumazenil is not useful for barbiturate- or opioid-induced sedation.

Basics

1. Dose: 0.01 mg/kg IV (max. dose 0.2 mg) If desired level of consciousness is not obtained after waiting an additional 45 seconds, give repeat dose.
2. Repeat dose: 0.005–0.01 mg/kg IV
3. Induction time: 1–3 min (peak effect 6–10 min)
4. Duration of effect:Usually less than 60 minutes. Duration is related to the dose given and the benzodiazepine plasma concentrations; reversal effects of flumazenil may be shorter than the effects of the benzodiazepine.

Nursing Considerations

Re-sedation may occur because the duration of effect of the benzodiazepine may exceed that of flumazenil. In the event of re-sedation, repeat doses may be administered at 20-minute intervals as needed.

Precautions

1. Should not be given to patients who are on benzodiazepines as part of therapy for a seizure disorder.
2. Give cautiously to patients who are on medications known to lower the seizure threshold, such as tricyclic antidepressants, theophylline, isoniazid or lithium. Use of flumazenil in these patients could precipitate a seizure.

Naloxone

Naloxone is a short-acting agent that reverses opioid-induced sedation. It competes and displaces opioids at opioid-receptor sites. Re-sedation may occur due to its short duration of action, therefore repeated doses are usually needed. Naloxone is not useful for barbiturate-, benzodiazepine- or phencyclidine-induced sedation.

Basics

1. Dose: 0.01 mg/kg (IV) over 30 sec as undiluted preparation
2. Repeat dose: 0.01 mg/kg IV may be repeated every 2–3 min as needed based on response
3. Induction time: Within 2 min
4. Duration of effect: 20–60 min. Duration is shorter than that of most opiates, therefore repeated doses are usually needed.

Clinical Effects

1. Re-sedation may occur, because the duration of effect of the opiate may exceed that of naloxone. In the event of re-sedation, repeat doses may be administered.
2. Naloxone may improve alertness but should not be substituted for an adequate period of postprocedure monitoring. Monitoring (including blood pressure) must continue until the child returns to and maintains his or her baseline level of consciousness.
3. Naloxone may precipitate withdrawal symptoms (hypertension, sweating, agitation, irritability, shrill cry, failure to feed) in opioid-dependent children. Use cautiously in children on opioid drips.