Inhalation of volatile industrial solvents and solvents from aerosol sprays can cause a state of intoxication. Chronic use can result in neuropathies and hepatotoxicity.
Use of volatile solvents (eg, acetates, alcohol, chloroform, ether, aliphatic and aromatic hydrocarbons, chlorinated hydrocarbons, ketones) continues to be an endemic problem among adolescents. Common commercial products (eg, glues and adhesives, paints, paint strippers, cleaning fluids) contain these substances; thus, children and adolescents can easily obtain them. About 10% of adolescents in the US have reportedly inhaled volatile solvents. Typically, a solvent-soaked rag is placed in a bag or container that is held to the mouth and nose; the naturally volatilized vapors are then inhaled (huffing, sniffing).
Volatile solvents temporarily stimulate the CNS before depressing it. Partial tolerance and psychologic dependence develop with frequent use, but a withdrawal syndrome does not occur.
Acute symptoms of dizziness, drowsiness, slurred speech, and unsteady gait occur early. Impulsiveness, excitement, and irritability may occur. As effects on the CNS increase, illusions, hallucinations, and delusions develop. Users experience a euphoric, dreamy high, culminating in a short period of sleep. Delirium with confusion, psychomotor clumsiness, emotional lability, and impaired thinking develop. The intoxicated state may last from minutes to > 1 h.
Sudden death can result from respiratory arrest or airway occlusion due to CNS depression or arrhythmias ("sudden sniffing death," perhaps due to myocardial sensitization).
Methylene chloride (dichlormethane) is metabolized to carbon monoxide and inhalation of this product can cause delayed onset of symptoms of carbon monoxide poisoning; symptoms may persist for a prolonged period.
Methanol inhalation may cause metabolic acidosis and retinal injury.
Chronic inhalation of volatile hydrocarbons may irritate the skin around the mouth and nose (huffer's eczema).
Complications of chronic use may result from the effect of the solvent or from other toxic ingredients (eg, lead in gasoline). Carbon tetrachloride may cause a syndrome of hepatic and renal failure. Toluene may cause degeneration of CNS white matter, renal tubular acidosis and hypokalemia. Injuries to brain, peripheral nerves, liver, kidneys, and bone marrow may result from heavy exposure or hypersensitivity.
Inhalant abuse during pregnancy can cause premature birth and fetal solvent syndrome, which has features similar to those of fetal alcohol syndrome.
Treatment for acute toxicity is supportive. Use of catecholamines (eg, for hypotension) should be avoided because of possible solvent-induced myocardial sensitization. Treatment of dysrhythmias is challenging and there is no specific treatment guideline. Beta blockers may have some benefit.
Treatment of solvent-dependent adolescents is difficult, and relapse is frequent. However, most users stop solvent use by the end of adolescence. Intensive attempts to broadly improve patients’ social skills and status in family, school, and society may help. For symptoms and treatment of poisoning with specific solvents, see Table: Symptoms and Treatment of Specific Poisons.