Alfentanil

CAS RN: 71195-58-9

Treatment Overview

0.4.2 ORAL/PARENTERAL EXPOSURE
  • A) DECONTAMINATION
    • 1) PREHOSPITAL: Opioid overdoses are life threatening. Activated charcoal should be considered early after a significant oral ingestion, if a patient can protect their airway and is without significant signs of toxicity. If a patient is displaying signs of moderate to severe toxicity, do NOT administer activated charcoal because of the risk of aspiration.
    • 2) HOSPITAL: Consider activated charcoal if a patient presents soon after an ingestion and is not manifesting signs and symptoms of toxicity. Activated charcoal is generally not recommended in patients with significant signs of toxicity because of the risk of aspiration. Gastric lavage is not recommended as patients usually do well with supportive care.
  • B) MANAGEMENT OF MILD TO MODERATE TOXICITY
    • 1) Patients may only need observation.
  • C) MANAGEMENT OF SEVERE TOXICITY
    • 1) Administer oxygen and assist ventilation for respiratory depression. Naloxone is the antidote indicated for severe toxicity (respiratory or CNS depression). Orotracheal intubation for airway protection should be performed early in cases of obtundation and/or respiratory depression that do not respond to naloxone.
  • D) AIRWAY MANAGEMENT
    • 1) Administer oxygen and assist ventilation for respiratory depression. Orotracheal intubation for airway protection should be performed early in cases of obtundation and/or respiratory depression that do not respond to naloxone, or in patients who develop severe acute lung injury.
  • E) ANTIDOTE
    • 1) NALOXONE, an opioid antagonist, is the specific antidote. Naloxone can be given intravascularly, intramuscularly, subcutaneously, intranasally or endotracheally. The usual dose is 0.4 to 2.0 mg IV. In patients with suspected opioid dependence, incremental doses of 0.2 mg IV should be administered, titrated to reversal of respiratory depression and coma, to avoid precipitating acute opioid withdrawal. Doses may be repeated every 2 to 3 minutes up to 20 mg. Very high doses are rarely needed, but may be necessary in overdoses of high potency opioids, like fentanyl.
    • 2) A CONTINUOUS infusion may be necessary in patients that have ingested a long-acting opioid. A suggested starting rate is two-thirds of the dose effective for initial reversal that is administered each hour; titrate as needed. DURATION of effect is usually 1-2 hours. Many opioids have a much longer duration of effect, so it may be necessary to observe the patient at least 3-4 hours after the last dose of naloxone to ensure that the patient does not have recurrent symptoms of toxicity. Naloxone can precipitate withdrawal in an opioid-dependent patients, which is usually not life-threatening; however it can be extremely uncomfortable for the patient.
  • F) SEIZURE
    • 1) Seizures are rare, but may be a result of hypoxia or due to properties of certain agents (eg, meperidine, tramadol, propoxyphene). Treatment includes ensuring adequate oxygenation, and administering intravenous benzodiazepines; propofol or barbiturates may be indicated, if seizures persist.
  • G) ACUTE LUNG INJURY
    • 1) Acute lung injury can develop in a small proportion of patients after an acute opioid overdose. The pathophysiology is unclear. Patients should be observed for 4 to 6 hours after overdose to evaluate for hypoxia and/or the development of acute lung injury.
  • H) HYPOTENSION
    • 1) Hypotension is often reversed by naloxone. Initially, treat with a saline bolus, if patient can tolerate a fluid load, then adrenergic vasopressors to raise mean arterial pressure.
  • I) ENHANCED ELIMINATION
    • 1) Hemodialysis and hemoperfusion are not of value because of the large volume of distribution for opioids.
  • J) INTRATHECAL INJECTION
    • 1) Limited experience. Treat seizures (eg, benzodiazepines, barbiturates, propofol) and support blood pressure with fluids and pressors as needed. Naloxone infusion may be useful. Intubate and ventilate as needed. Cerebrospinal fluid drainage may accelerate recovery.
  • K) PATIENT DISPOSITION
    • 1) HOME CRITERIA: Respiratory depression may occur at doses just above the therapeutic dose. Children should be observed and evaluated in the hospital as they are generally opioid naive and may develop respiratory depression. Adults should be evaluated by a health care professional if they have received a higher than recommended (therapeutic) dose, especially if opioid naive.
    • 2) OBSERVATION CRITERIA: Patients with deliberate ingestions or a pediatric ingestion should be sent to a health care facility for observation for at least 4 hours, to ensure that peak plasma levels have been reached and there has been sufficient time for symptoms to develop. Patients that have ingested a sustained release or long acting product have the potential to manifest symptoms in a delayed fashion and should be observed for 24 hours. Patients who are treated with naloxone should be observed for 4 to 6 hours after the last dose, for recurrent CNS depression or acute lung injury.
    • 3) ADMISSION CRITERIA: Patients with significant, persistent central nervous system depression should be admitted to the hospital. A patient needing more than 2 doses of naloxone should be admitted as a longer-acting opioid has likely been taken; additional doses may be needed. Patients with coma, seizures, dysrhythmias, delirium, and those needing a naloxone infusion or who are intubated should be admitted to an intensive care setting.
    • 4) CONSULT CRITERIA: Consult a poison center or medical toxicologist for assistance in managing patients with severe toxicity or in whom the diagnosis is not clear.
  • L) PITFALLS
    • 1) Patients may be discharged prematurely after mental status clears with a dose of naloxone. Naloxone's duration of effect may be much shorter than the duration of effect for many opioids. Other causes of altered mental status must be ruled out, such as hypoxia or hypoglycemia.
  • M) PHARMACOKINETICS
    • 1) Opioids may be absorbed via many routes, most commonly oral or transdermal for pain control. Abusers may inject, snort or smoke an opioid (these routes rapidly achieve high serum levels), which can produce euphoria quickly and place the individual at risk for severe toxicity. Opioids slow GI motility, which may lead to prolonged absorption.
  • N) DIFFERENTIAL DIAGNOSIS
    • 1) Overdose with other sedating agents (e.g., ethanol, benzodiazepine/barbiturate, antipsychotics); overdose with central alpha 2 agonists (e.g., clonidine, tizanidine, imidazoline decongestants); CNS infection; intracranial hemorrhage; hypoglycemia or hypoxia.
0.4.3 INHALATION EXPOSURE
  • A) Inhalation of opioids may result from intentional crushing and "snorting" of tablets or smoking heroin. Refer to ORAL exposure for further treatment guidelines.
0.4.6 PARENTERAL EXPOSURE
  • A) INTRATHECAL INJECTION: Limited experience. Treat seizures (ie, benzodiazepines, barbiturates, propofol) and support blood pressure with fluids and pressors as needed. Naloxone infusion may be useful. Intubate and ventilate as needed. Cerebrospinal fluid drainage may accelerate recovery. Refer to ORAL exposure for further treatment guidelines.
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