Definition and Epidemiology
Inhalant use disorder (IUD) is the chronic (> 12 months), problematic pattern of inhalant use causing significant distress.
- Inhalants are typically volatile hydrocarbons that are in a gaseous state at room temperature.
- As with other substance use disorders, those with IUDs develop:
- Physical tolerance
- Impairment in their daily functioning
- Among the most easily and widely available substances for misuse, especially in younger populations
- Lifetime prevalence: 11% of high school students in the United States report use at some point.
- Approximately same use among men and women
- 20% of emergency department encounters secondary to inhalant use disorder occur in those < 18 years of age.
- Mental health comorbidities: major depression, suicidality, conduct disorder, abuse of other drugs
Types of inhalants
There are 4 commonly used types of inhalants with slightly different effects and side effects.
- Volatile solvents:
- Found in common household items such as glue and adhesives, paint thinners, gasoline, and marker tips
- Most often used substance in young adolescents
- Very toxic to the liver, bone marrow, and kidneys
- Aerosols: contained in hair spray, cooking spray, spray paint
- Gases: ether, halothane, nitrous oxide (also known as whippets)
- Organic nitrates:
- Include amyl nitrate, isobutyl nitrate
- Used as anal sexual intercourse enhancers because they relax smooth muscle
- Cause dizziness, tachycardia, hypotension, flushing
- Associated with vitamin B deficiency → might lead to polyneuropathy
- Might lead to methemoglobinemia
- Lipoid pneumonia and death from aspiration of liquid form
- Volatile hydrocarbons and nitric oxide are highly lipid-soluble → rapidly absorbed across the pulmonary capillary bed into the bloodstream → distributed throughout the body
- Onset is rapid and duration is relatively short.
- Neurons (high lipid content) are highly affected by inhalants.
- CNS depression by alteration of neuronal membrane function at glutamate or GABA receptors
- Concentration of inhalant substances increase when they are taken with alcohol → both substances metabolized by the liver
Clinical Presentation and Diagnosis
- Muscle weakness
- Dilated pupils
- Slurred speech
- Perceptual disturbances, paranoia
- Lethargy, clouding of consciousness
- Respiratory depression
- Cardiac arrhythmias
- Nasal crusting
- Rash (dermatitis)
A withdrawal syndrome does not usually occur. However, the following symptoms may appear:
- Craving and irritability
- Sleep disturbance
- Increased sweating
- Muscle aches
- Supportive care: monitor airway, breathing, and circulation
- Identify solvent: Some substances (e.g., leaded gasoline) may require specific treatment, such as chelation.
- Avoid use of hypnotics during acute intoxication and use antipsychotics in cases of acute agitation.
- Supportive care
- Psychotherapy as well as group therapy
- Hyperbaric chambers
- May take up to 28 weeks to get substance out of the system
- No proven treatment available for cognitive impairments caused by inhalants
- Psychologic counseling
- Community prevention and treatment programs
- Neurocognitive impairment
- Cerebellar dysfunction
- Peripheral neuropathy
- Metabolic acidosis
- Urinary calculi
- Aplastic anemia
- Methemoglobinemia: Nitrites can oxidize iron, converting it into a state of lower affinity to oxygen and higher affinity to cyanide, leading to tissue hypoxia. Nitrites may be absorbed through dietary intake, polluted high-altitude water sources, and local anesthetics. Treatment involves the administration of methylene blue and vitamin C. History of inhalant usage as well as persisting hypoxemia after oxygen supplementation distinguish this diagnosis from inhalant use disorder.
- Cannabis use disorder: Cannabis (marijuana) is the most commonly used illicit substance worldwide. Intoxication symptoms include euphoria, laughter, lethargy, conjunctival injection, and increased appetite. Withdrawal symptoms include irritability, anxiety, insomnia, and decreased appetite. Cannabis is popular in a similar demographic as for inhalants. Careful history taking of the substance ingested and urine testing can help in distinguishing inhalant ingestion from cannabis use.
Alcohol use disorder: level of alcohol consumption exceeding the sociocultural standard. Marked by a mental and physical addiction with an irresistible desire for the substance and development of tolerance with a consecutive increase of dosage and withdrawal symptoms during abstinence. While intoxication with alcohol and inhalants may present very similarly, careful history taking and alcohol breath testing can help in distinguishing one from the other.
- Eaton, D. K., Kann, L., Kinchen, S., et al. (2012). Youth risk behavior surveillance—United States, 2011. MMWR Surveillance Summaries 61(4):1–162.
- Sakai, J. T., Hall, S. K., Mikulich-Gilbertson, S. K., Crowley, T. J. (2004). Inhalant use, abuse, and dependence among adolescent patients: commonly comorbid problems. Journal of the American Academy of Child and Adolescent Psychiatry 43(9):1080–1088. https://doi.org/10.1097/01.chi.0000132813.44664.64
- Thompson, A. (2021). Clinical Management of Drug Use Disorders. DeckerMed Medicine.
- Sadock, B. J., Sadock, V. A., Ruiz, P. (2014). Substance use and addictive disorders. Chapter 20 of Kaplan and Sadock’s Synopsis of Psychiatry: Behavioral Sciences/Clinical Psychiatry, 11th ed. Philadelphia: Lippincott Williams and Wilkins, pp. 656–659.