Opioid toxicity

Background

• Obtain acetaminophin levels in all cases of combination opioid-acetaminophen overdoses
• Respiratory depression is the cause of all mortality from opioid toxicity
• When prescribing opioid pain relievers in the ED, remember to have a discussion of co-ingestion of other depressants (alcohol involved in 1/5 of opioid related deaths)
• Consider contributing to the DAWN database for public ED research benefit (Drug Abuse Warning Network)
• Other than common co-ingestions, consider adulterants such as amphetamines, anticholinergics, hypnotics, heavy metals, etc.

Clinical Features

1. Common
   1. Miosis
   2. N/V
   3. Respiratory depression
   4. Mental status depression
2. Uncommon
   1. QT prolongation (methadone)
   2. Seizure (tramadol)
   3. Acute lung injury
   4. Bowel obstruction, rupture (body packers)
   5. Noncardiogenic pulmonary edema (1-2% of heroin overdoses)
      1. Within 2-4 hrs of overdose
      2. Increased RR, cough, pink frothy sputum, CXR with b/l infiltrates
      3. Resolves in 24-48 hrs with respiratory supportive care

Differential Diagnosis

• Clonidine toxicity
• Organophosphate toxicity
• CO poisoning
• Hypoglycemia
• Postictal state
• CVA - pontine hemorrhage (miosis, coma)
• ARDS
• DKA, hyperosmolar coma

Sedative/hypnotic toxicity

• Absinthe
• Barbiturates
• Benzodiazepines
  • Flunitrazepam (Rohypnol)
• Chloral hydrate
• Gamma hydroxybutyrate (GHB)
• Baclofen toxicity
• Opioids
  • Lomotil toxicity
  • Loperamide toxicity
• Toxic alcohols
  • Ethanol
  • Ethylene glycol
  • Isopropyl alcohol
  • Methanol
• Xylazine toxicity
• Phencyclidine toxicity
• Phenothiazine toxicity

Treatment

1. Airway protection and ventilatory management
   • BVM and naloxone administration may prevent need for intubation
2. Naloxone (Narcan)
   • Bolus (May repeat q3min up to max dose 10mg
     • Apneic or near-apneic - 2mg IV
     • Opioid-naive with minimal respiratory depression - 0.4mg IV
     • Opioid-dependent with minimal respiratory depression - 0.05mg IV
     • Almost immediate onset of action
     • Duration of action = 20-90min (may be less than that of the ingested opioid)
   • Infusion
     • Only give if the pt responded to the bolus and required repeat administration
     • Step 1: Determine the "wake-up dose" or bolus required to wake the pt
     • Step 2: Give 2/3 of the "wake-up dose" per hr; mix in 1L D5W
3. GI decontamination
   • Activated charcoal x1 if opioid ingestion occurred within 1hr

Disposition

1. Heroin intoxication:
   1. Consider discharge 1-2hr after naloxone administration if all are true:
      1. Independent mobility
      2. O2 sat >92% (room air)
      3. RR >10bpm
      4. HR >50
      5. Normal temp
      6. GCS 15
2. Non-heroin intoxication:
   1. Consider discharge after 4-6hr obs
3. Consider discharge with Rx for Naloxone
   • Naloxone 2 mg/2 mL prefilled syringe and intranasal atomizer device
     #2 each
     Spray one-half of syringe (1 mL) into each nostril upon signs of opioid overdose. May repeat X 1. Call 911.

See Also

• Opioid withdrawal

External Links

• MDCalc - Opiod Risk Tool (ORT) for Narcotic Abuse