Learning objectives

• Signs and symptoms of heroin or opioid toxicity
• Treatment and perioperative management of heroin or opioid toxicity

Definition and mechanisms

• Heroin, also known as diacetylmorphine, is a potent opioid mainly used as an illegal recreational drug for its euphoric effects
• Very addictive and known for causing significant withdrawal symptoms and can be sniffed, smoked, or injected
• When administered intravenously, heroin has two to three times the effect of a similar dose of morphine
• Heroin has an average half-life of three minutes in blood after intravenous administration, requiring drug users to use it several times per day to maintain the effect
• Tolerance usually develops over time
• Heroin levels peak after five minutes of intranasal or intravenous uptake, but its potency after intranasal usage is about half of intravenous usage
• The three most clinically relevant opioid receptors are the µ-, κ-, and δ-receptors:
  • Stimulation of central µ-receptors causes respiratory depression, analgesia (supraspinal and peripheral), and euphoria
  • κ- and δ-receptors also have potent analgesic effects, and stimulation leads to disassociation, hallucinations, and dysphoria
  • δ-receptors are thought to influence mood

Signs and symptoms

Opiate withdrawal symptoms

• Symptoms are not life-threatening
  • Alertness
  • Muscle pain
  • Dilated pupils
  • Piloerection
  • Sweating
  • Vomiting and diarrhea
  • Pain
  • Aspiration
  • Insomnia
  • Yawning
• Medications to treat opiate withdrawal symptoms
  • Methadone (long-acting opioid)
  • Buprenorphine (partial mu agonist and kappa antagonist)
  • Clonidine and lofexidine (alpha-2 adrenergic agents)

Complications 

• Intravascular infections and infectious disease transmission (HIV, hepatitis B, and C) due to shared needles
• The needle can break off → embedded foreign body
• Skin infections: cellulitis and abscess
• Compartment syndrome
• Intravascular infections can grow on the heart valves → valve replacement
• Septic emboli → empyema
• Hypoxic end-organ damage secondary to hypoventilation
• Acute lung injury
• Narcotic bowel syndrome 
• Withdrawal symptoms

Diagnosis

• Blood and urine test
• Chest X-ray
• CT scan
• ECG

Management 

Perioperative management

Refer to opioid tolerance or methadon-using patients

Suggested reading

• World Health Organization. 2021. Opioid overdose. https://www.who.int/news-room/fact-sheets/detail/opioid-overdose
• Volkow ND, Jones EB, Einstein EB, Wargo EM. Prevention and Treatment of Opioid Misuse and Addiction: A Review. JAMA Psychiatry. 2019;76(2):208-216.
• Simpson, G., Jackson, M., 2017. Perioperative management of opioid-tolerant patients. BJA Education 17, 124–128.
• Nicholson Roberts, T., Thompson, J.P., 2013. Illegal substances in anaesthetic and intensive care practices. Continuing Education in Anaesthesia Critical Care & Pain 13, 42–46.
• Boyer EW. Management of opioid analgesic overdose. N Engl J Med. 2012;367(2):146-155.