- Etiology & Epidemiology
- Intentional inhalation of volatile substances found in common household or industrial products (e.g., glue, solvents, spray paints, gasoline, paint thinners).,
- Predominantly abused by young children and adolescents due to easy accessibility and low cost.,
- Specific types include:
- Solvents: Toluene, gasoline.
- Aerosols: Spray paints, deodorants.
- Gases: Nitrous oxide (“whippets”), butane lighters.
- Nitrites: Amyl nitrite (“poppers”), often used for sexual enhancement.
- Mechanism of Action
- Most are CNS depressants, with effects similar to alcohol. The mechanism is not fully understood but may involve potentiation of GABA-A receptors and inhibition of NMDA receptors.
- Inhalants are highly lipid-soluble, allowing for rapid absorption through the lungs and entry into the CNS.
- Clinical Features (Acute Intoxication)
- Effects are rapid in onset and short in duration (minutes), leading to repeated use.,
- Sx resemble alcohol intoxication: euphoria, slurred speech, dizziness, ataxia, disorientation, lethargy.
- Classic physical finding: Perioral or perinasal rash (“glue sniffer’s rash”) or stains from paint/substances on the hands or face.,
- May also cause hallucinations, headache, nausea, and vomiting.,
- Diagnosis
- Primarily a clinical diagnosis based on Hx and physical exam findings (e.g., chemical odor on breath/clothes, rash).,
- Routine urine toxicology screens do not detect most common inhalants like toluene.
- Toxicity & Long-Term Complications
- Cardiac: “Sudden sniffing death syndrome” is a key and devastating complication, even in first-time users. It is caused by a fatal cardiac arrhythmia, as the volatile hydrocarbons sensitize the myocardium to catecholamines., A sudden surge of epinephrine (e.g., from being startled) can trigger ventricular fibrillation.
- Neurologic:
- Permanent brain damage, including cortical atrophy, cerebellar dysfunction (ataxia), and cognitive impairment (dementia).,
- Hearing loss (toluene).
- Peripheral neuropathy.
- Renal:
- Toluene is classically associated with Type 1 (distal) renal tubular acidosis (RTA), leading to a hypokalemic, hyperchloremic non-anion gap metabolic acidosis.,,
- Acute toxicity can also cause a high anion gap metabolic acidosis due to the accumulation of hippuric acid, a toluene metabolite.,
- Other:
- Benzene (found in gasoline) can cause aplastic anemia and bone marrow suppression.
- Liver damage (hepatitis).
- Lung damage (emphysema-like changes).
- Withdrawal
- A withdrawal syndrome can occur in chronic users, though often considered less severe than with other substances.
- Symptoms include anxiety, irritability, sleep disturbance, nausea, and diaphoresis.