Heroin or opioid toxicity

Learning objectives

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

Respiratory system	Respiratory depression - No breathing - Shallow breathing - Slow and difficult breathing
Nervous system	Dry mouth Extremely small pupils (pinpoint pupils) Delirium Disorientation Drowsiness Seizures Muscle spasms Coma
Cardiovascular system	Hypotension Weak pulse
Skin	Bluish-colored nails and lips
Gastrointestinal system	Constipation Spasms of the stomach and intestines

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)

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