Heroin
Epidemiology
Pharmacology
- Heroin is diacetylmorphine
- Higher lipid solubility than morphine -> crosses blood-brain barrier more readily than morphine
Adverse Effects
- Acute Hypoventilation (see [[Acute Hypoventilation]])
- Acute Lung Injury-ARDS (see [[Acute Lung Injury-ARDS]])
- Epidemiology
- Probably the most common drug-induced pulmonary disease worldwide
- May occur with first use of heroin
- Probably dose-related (although exact dose is usually unknown)
- 40% of acute overdoses have heroin-induced pulmonary edema
- Possible Physiologic Mechanisms
- Direct toxic effect on alveolar-capillary membrane -> increased alveolar-capillary membrane permeability
- Neurogenic response to CNS injury
- Allergic or hypersensitivity reaction
- Acute hypoxic effect on alveolar-capillary membrane -> secondary increase in alveolar-capillary membrane permeability
- However, other agents that depress the respiratory center (barbiturates) rarely induce pulmonary edema
- Diagnosis
- ABG: metabolic and respiratory acidosis
- CXR/Chest CT: bilateral alveolar infiltrates
- Clinical
- Dyspnea usually occurs within minutes of drug injection (although some cases may occur even hours-days later)
- 50% of cases may have complicating aspiration pneumonia -> aspiration should be suspected in cases where infiltrates do not clear within 24-48 hrs
- Treatment
- Supportive
- Avoid corticosteroids (especially in setting of suspected aspiration
- Antibiotics: if aspiration is suspected
- Prognosis
- Decreased DLCO on PFT’s may be persistently observed even after infiltrates have cleared
- Recurrent Aspiration Pneumonia with Bronchiectasis (see [[Aspiration Pneumonia]] and [[Bronchiectasis]])
- Epidemiology: cases have been reported in chronic heroin users
- Physiology: probably related to recurrent aspiration
- Necrotizing Bronchitis (see [[Aspiration Pneumonia]])
- Epidemiology: cases have been reported in chronic heroin users
- Physiology: probably related to recurrent aspiration
- Talc/Foreign Body Granulomatosis (see [[Foreign Body Granulomatosis]])
- Epidemiology: seen in chronic heroin IVDA
References
