Inhalant

Overview
Inhalants are drugs that are inhaled as a gas, vapor, or aerosol. Some inhalants are used for medical purposes, such as anesthesia and the delivery of medication to the lungs (for example by an inhaler or nebulizer to administer asthma medication.) Other inhalants are used recreationally, such as organic solvents and propellant gases. Some inhalants, such as ether and alkyl nitrites, have been widely used both medically and recreationally.

Effects of recreational solvent inhalation can range from an alcohol-like intoxication and euphoria to hallucinations. Toxicity and death may also result. Nonmedical inhalant use is restricted and even criminalized in some jurisdictions.

Solvents and propellants
Solvents and propellants used as inhalants are found in a range of inexpensive, legally-available household, office, industrial, and automotive products.

A number of household and office products contain solvents that are used as inhalants, such as toluene and acetone. These products include correction fluids such as Liquid Paper, nail polish removers (acetone), and permanent markers (xylene). Propellant gases used as inhalants in household and office products include freon and compressed hydrofluorocarbons, which are used in various household and office products that come in aerosol spraycans, such as air freshener, computer keyboard cleaner spray (canned air), non-stick cooking spray, aerosol insecticides, and aerosol hairspray. Another household product which contains propellant gases that are used as an inhalant is aerosol whipped cream cans, which contain nitrous oxide gas. Various insecticides such as Raid are also used.

Industrial and automotive products also contain solvents and propellant gases that are used as inhalants. Solvents such as toluene are found in turpentine, gasoline, paint, spraypaint, an a range of quick-drying adhesives and cements (e.g., rubber cement and plastic cement). The solvent diethyl ether is used in an aerosol product called automotive starting fluid, which is used to help carburetor engines start in frigid weather. Canisters of butane are used in inexpensive home welding kits.

Nitrites
Several nitrite drugs called "poppers" are used for their euphoric effect in the gay subculture and in the rave dance scene. While nitrite drugs are regulated by a variety of federal and local regulations and legal restrictions, several nitrite products can be found in legally-available products. Amyl nitrite is available as an over-the-counter drug in some areas; butyl nitrite is sold as a room deodorizers under trade names as "RUSH" and "Locker Room"; and alkyl nitrite is an ingredient in video head cleaner or some brands of nail polish remover.

Mechanisms of action
Inhalants are a large class of drugs and therefore exhibit a variety of mechanisms of action. The mechanisms of action of many non-medical inhalants has not been well elucidated.

Anesthetic gases used for surgery, such as nitrous oxide or enflurane, are believed to induce anesthesia primarily by acting as NMDA antagonists, open channel blockers which bind to the inside of the calcium channels on the outer surface of the neuron, and provide high levels of NMDA receptor blockade for a short period of time.

This makes inhaled anesthetic gases different to other NMDA antagonists such as ketamine, which bind to a regulatory site on the NMDA-sensitive calcium transporter complex and provide slightly lower levels of NMDA blockade, but for a longer and much more predictable duration. This makes a deeper level of anesthesia achievable more easily using anaesthetic gases, but can also make them more dangerous than other drugs used for this purpose.

Alcohol is known to act as a GABA agonist, and it is likely that other solvents also act here to produce additional depressant effects. The solvent diethyl ether, for instance, has seen historical episodes of both inhalation and drinking, and produces effects suggestive of both kinds of activity. The particular mix of NMDA antagonist vs GABA agonist properties will vary between solvents depending on molecular size or shape, and so the effects of particular solvents will differ, although all tend to share a similar profile

Methods of Psychoactive Inhalant use and effects
Inhalant users inhale vapors or aerosol propellant gases using plastic bags held over the mouth or by breathing from an open container of solvents, such as gasoline or paint thinner. Nitrous oxide gases from whipped cream aerosol cans and aerosol hairspray or non-stick frying spray is sprayed into plastic bags; some users may filter the aerosolized particles out with a rag. Some gases such as propane and butane gases are inhaled directly from the canister.

Once these solvents or gases are inhaled, the extensive capillary surface of the lungs rapidly absorb the solvent or gas, and blood levels peak rapidly. The intoxication effects occur so quickly that the effects of inhalation can resemble the intensity of effects produced by intravenous injection of other psychoactive drugs.

The effects of solvent intoxication can vary widely depending on the dose and what type of solvent or gas is inhaled. A person who has inhaled a small amount of rubber cement or paint thinner vapour may be impaired in a manner resembling alcohol inebriation - stimulation, a sense of euphoria and intoxication, followed by a period of depression. A person who has inhaled a larger quantity of solvents or gases, or a stronger chemical may experience to stronger effects such as distortion in perceptions of time and space, hallucinations, and emotional disturbances.

In the short term, many users experience headache, nausea and vomiting, slurred speech, loss of motor coordination, and wheezing. A characteristic "glue sniffer's rash" around the nose and mouth is sometimes seen after prolonged use. An odor of paint or solvents on clothes, skin, and breath is sometimes a sign of inhalant abuse, and paint or solvent residues can sometimes emerge in sweat.



Dangers associated with psychoactive inhalants
Psychoactive inhalant users can be injured or killed due to the effects of inhaling these solvents or gases, which can cause hypoxia (lack of oxygen), pneumonia, cardiac failure or arrest, or aspiration of vomit. Other inhalant users are injured due to the harmful effects of other chemicals used in these products (e.g., tetraethyl lead used in some fuels) or due to dangerous behavior while they are intoxicated.

The inhaling of some solvents can cause irreversible effects such as hearing loss, limb spasms, and damage to the central nervous system and brain. Serious but potentially reversible effects include liver and kidney damage and blood oxygen depletion. Death from inhalants is usually caused by a very high concentration of fumes. Deliberately inhaling from an attached paper or plastic bag or in a closed area greatly increases the chances of suffocation.

Of more concern from a toxicological perspective, or from the point of view of an individual considering the recreational use of solvents, is the additional toxicity resulting from either the physical properties of the compound itself, or additional ingredients present in a product. Many solvents of abuse are fairly toxic compounds which often produce liver and brain damage after prolonged use. This is particularly bad with chlorinated compounds such as carbon tetrachloride or chloroform, or when products containing mixtures of many substances such as glue or paint is inhaled.

Toxicity may also result from the pharmacological properties of the drug; excess NMDA antagonism can completely block calcium influx into neurons and provoke cell death through apoptosis, although this is more likely to be a long term result of chronic solvent abuse than a consequence of short term use.

Solvents
Use of inhalants can cause brain, nerve, liver and other damage to the body. In the short term, death from solvent abuse occurs most commonly from aspiration of vomit while unconscious, or from a combination of respiratory depression and hypoxia, the second cause being especially a risk with heavier than air vapors such as butane or gasoline vapor. Deaths typically occur from complications related to excessive sedation and vomiting. Actual overdose from the drug does occur, however, and indeed inhaled solvent abuse is statistically more likely to result in life-threatening respiratory depression than intravenous use of opiates such as heroin.

Most deaths from solvent abuse could be prevented if individuals were resuscitated quickly when they stopped breathing and their airway cleared if they vomited. However, most inhalant abuse takes place when people inhale solvents by themselves or in groups of people who are intoxicated. Certain solvents are more hazardous than others, such as gasoline or refrigerant gases.

Hypoxia can occur when inhalant users are huffing from a plastic bag over their face, which means that they are not breathing enough fresh air. However, some inhalants are heavier-than-air gases or vapors, and, if regular breathing is not maintained, they will remain in the lungs instead of being naturally expelled. Also, since many solvents are highly flammable (e.g., gasoline, paint thinner), some users have suffered burn injuries and deaths due to fires.

Female inhalant users who become pregnant may have adverse effects on the fetus. The baby may be smaller, and may need additional health care. There is some evidence of birth defects and disabilities in babies born to women who sniffed solvents such as gasoline. Driving while using solvents presents the same dangers as other types of impaired driving, because many solvents cause an alcohol-type intoxication. In 1999, five high school girls were killed in a car accident outside Philadelphia after the driver and three of the passengers had inhaled computer keyboard cleaner.

Other inhalants
Inhaling butane gas can cause drowsiness, narcosis, asphyxia, cardiac arrhythmia and frostbite. Butane is the most commonly misused volatile solvent in the UK, and caused 52% of solvent related deaths in 2000. By spraying butane directly into the throat, the jet of fluid can cool rapidly to –20 °C by expansion, causing prolonged laryngospasm. Some inhalants can also indirectly cause sudden death by cardiac arrest, in a syndrome known as Sudden Sniffing Death Syndrome. The anesthetic gases present in the inhalants appear to sensitize the user to adrenaline. In this state a sudden surge of adrenaline (e.g., from a frightening hallucination or run in with the law), can cause a fatal cardiac arrhythmia.

Nitrous oxide gas can cause death by asphyxiation if a user inhales directly from a large tank using a mask or tube. Normally with recreational use, users get oxygen because they continue to breathe after inhaling the nitrous oxide from a bag or balloon. However, if a mask is attached to the tank, then the user gets pure nitrous oxide with no way to take in any oxygen. The rapidly-expanding gas causes very cold temperatures which can freeze the lips and throat if the gas is inhaled directly from a tank or "whippit" aerosol container. Releasing the gas into a balloon first allows the gas to expand and warm before it is inhaled.

Death statistics
Precise statistics on deaths caused by inhalant abuse are difficult to determine, as it is considered a dramatically under-reported cause of death due to the common result of a cause-of-death determination being attributed to the side-effects of inhalant abuse (such as a blood vessel rupture in the brain or a heart attack) rather than to the abuse itself.

Inhalant use or abuse was mentioned on 144 death certificates in Texas during the period 1988-1998 and was reported in 39 deaths in Virginia between 1987 and 1996 from acute voluntary exposure to abused inhalants.

Socioeconomics of inhalant abuse
Inhalant drugs are often used by children, teenagers, incarcerated or institutionalized people, and impoverished people, because these solvents and gases are ingredients in hundreds of legally-available, inexpensive products, such as aerosol spray cans, adhesives and rubber cements, deodorant sprays, hair spray, air fresheners, gasoline, lighter fluid, paint, and paint thinner.

Inhalants are used by a wide cross section of society, including children, teenagers, and adults, in lower-income, middle-income, and even upper-income settings, because inhalant drugs are a legal and easily available source of a "high." However, most users tend to be "...adolescents (between the ages of 13 and 17)" In some countries, chronic, heavy inhalant use is concentrated in marginalized, impoverished communities ).

Young people who become chronic, heavy inhalant abusers are also more likely to be those who are isolated from their families and community. The article Epidemiology of Inhalant Abuse: An International Perspective notes that "[t]he most serious form of obsession with inhalant use probably occurs in countries other than the United States where young children live on the streets completely without family ties. These groups almost always use inhalants at very high levels (Leal et al. 1978). This isolation can make it harder to keep in touch with the sniffer and encourage him or her to stop sniffing." The article also states that "...high [inhalant use] rates among barrio Hispanics almost undoubtedly are related to the poverty, lack of opportunity, and social dysfunction that occur in barrios", and states that the "...same general tendency appears for Native-American youth", because "...Indian reservations are among the most disadvantaged environments in the United States; there are high rates of unemployment, little opportunity, and high rates of alcoholism and other health problems."

There is a wide range of social problems associated with inhalant use such as feelings of distress, anxiety and grief for the community; violence and damage to property, violent crime, stresses on the juvenile justice system, and stresses on youth agencies and support services.

History of inhalants
Solvents such as chloroform and diethyl ether and gases such as nitrous oxide were first used for medical purposes, such as providing anesthesia. These solvents' psychoactive and hallucinogenic effects at sub-anesthetic levels was also noted, which led to recreational use. Nitrous oxide particularly was popularised by the scientist Sir Humphry Davy who held nitrous oxide parties where users could enjoy the euphoric properties of the gas. Davy, noting the anesthetic effects, proposed that the gas could be used for operations, although this was not tried for another half century.

Chloroform was used as an anaesthetic, but it fell into disuse due to its high toxicity and narrow dose margin. Nitrous oxide and diethyl ether were adopted by the medical mainstream and became the standard anesthetics in use for many years. Other gases such as cyclopropane were also used for anesthesia. Non-flammable gases such as halothane replaced flammable anaesthetics such as ether. Halothane is now rarely used in humans due to problems with liver damage and a rare condition called malignant hyperthermia, but it is still widely used in veterinary medicine.

In modern times newer anesthetics such as isoflurane and sevoflurane have been developed for medical use which lack both the flammability of ether and the toxicity of halothane, and research in the area is ongoing. Nitrous oxide is still widely used as a dental anaesthetic, to reduce patient anxiety during dental work and minor dental surgery. Other medical anesthetics and inhaled medicinal drugs include xenon, enflurane, isoflurane, sevoflurane, desflurane, methoxyflurane, salbutamol, and fluticasone.

Legal issues
Most inhalant solvents and gases are not regulated under illegal drug laws such as the United States' Controlled Substances Act. However, many US states and Canadian cities have placed restrictions on the sale of some solvent-containing products to minors, particularly for products widely associated with "sniffing", such as model cement. The practice of inhaling such substances is sometimes colloquially referred to as huffing, sniffing (or "glue-sniffing"), dusting, or chroming.

Africa
Dung sniffing has also been seen in some African countries (see Jenkem). Glue sniffing is also a problem in these countries, with dung sniffing generally being a last resort by people too poor to afford glue.

India and South Asia
In India and South Asia, three of the most widely abused inhalants are the Dendrite brand and other forms of contact adhesives and rubber cements manufactured in Kolkata, toluenes in paint thinners and Iodex - a muscle stress relieving balm. Another very common inhalant is Erase-X, a correction fluid which contains toluene. It has become very common for school and college students to use it because it is easily available in stationery shops in India.

South East Asia
Dung sniffing has been noted as a problem in several countries in South East Asia such as Thailand and Malaysia among poor and homeless people. Animal or human dung is placed into a plastic bag or tin and left out in the sun where it starts to decompose, releasing methane gas, which has narcotic properties. Police were unsure of what action could be taken, given that dung is not illegal and would be problematic to restrict supplies.

UK
Generally exists in party cultures (using poppers)

Russia and Eastern Europe
Gasoline sniffing became common on Russian ships following attempts to limit the supply of alcohol to ship crews in the 1980s. The documentary Children Underground depicts the huffing of a solvent called Aurolac by Romanian homeless children. Gasoline sniffing also occurs in some remote indigenous communities in developed countries.

Canada
Native children in the isolated Northern Labrador community of Davis Inlet were the focus of national concern in 1993 when many were found to be sniffing gasoline. The federal Canadian and provincial Newfoundland and Labrador governments intervened on a number of occasions, sending many children away for treatment. Despite being moved to the new community of Natuashish in 2002, serious inhalant abuse problems have continued. Similar problems were also reported in Sheshatshiu in 2000.

Mexico
The inhaling of a mixture of gasoline and/or industrial solvents, known locally as "Activo" or "Chemo", has risen in popularity among the homeless and among the street children of Mexico City in recent years. The mixture is poured onto a handkerchief and inhaled while held in one's fist.

The chemicals in most common use are cements (trichloroethylene, tetrachloroethylene), lubricants (toluene, ethyl acetate and other acetones), thinners (petroleum distillants, benzene, acetone, tetrachloroethylene) and paint strippers (acetone, toluene, benzene, methylene chloride).

United States
Ether was used as a recreational drug during the 1930s Prohibition era, when alcohol was made illegal in the USA for over 10 years. Ether was either sniffed or drunk, and in some towns replaced alcohol entirely. However, the risk of death from excessive sedation or overdose is greater than that with alcohol, and ether drinking is associated with damage to the stomach and gastrointestinal tract.

Use of glue, paint and gasoline was little known before the 1950s. Later, glue sniffing became a worldwide phenomenon; however, it is not known if this popularity was caused by government anti-inhalant campaigns. Drug educators argue that the advertising campaigns designed to prevent drug use may instead promote such use. Abuse of aerosol sprays became more common in the 1980s as older propellants such as CFCs were phased out and replaced by more environmentally friendly compounds such as propane and butane.

Abuse of solvents is widespread in impoverished communities, both in developing countries or in poor communities in developed countries (e.g., Aboriginal communities in northern Canada or in Australia). Because solvents and inhalant gases are legally available and inexpensive, there has long been incidents of teenagers using inhalants recreationally. However, most of the long term abuse, or use by older adults tends to be limited to extremely poor or marginalised groups in society.

Australia
Although some sources argue that sniffing was introduced by US servicemen stationed in the nation's Top End during World War II, or through experimentation by 1940s-era Coburg Peninsula sawmill workers, other sources claim that inhalant abuse (such as glue inhalation) emerged in Australia in the late 1960s. Chronic, heavy gasoline sniffing appears mainly to occur among remote, impoverished indigenous communities, where the ready accessibility of gasoline has helped to make it a common substance for abuse.

In Australia, gasoline sniffing now occurs widely throughout remote communities of the Northern Territory, Western Australia, northern parts of South Australia and Queensland. The number of people sniffing gasoline goes up and down over time as young people experiment or sniff occasionally. 'Boss' or chronic sniffers may move in and out of communities; they are often responsible for encouraging young people to take it up.

A 1983 survey of 4,165 secondary students in New South Wales showed that solvents and aerosols ranked just after analgesics (e.g., codeine pills) and alcohol for drugs that were abused. This 1983 study did not find any common usage patterns or social class factors.

In Australia between 1981-1991, there were 60 Aboriginal males and three Aboriginal females whose deaths were associated with gasoline sniffing . They ranged in age from 11 to 32. The causes of death included pneumonia, cardiac failure/arrest, aspiration of vomit, and burns. In 1985, there were 14 communities in Central Australia reporting young people sniffing. In July 1997, it was estimated that there were around 200 young people sniffing gasoline across 10 communities in Central Australia. Approximately 40 were classified as 'chronic' sniffers.

In some communities many children and youths might try gasoline sniffing at least once or twice. Most of these 'experimental' users will not become regular or long-term sniffers. Recently, there have been reports of young Aboriginal people sniffing gasoline in the urban areas around Darwin and Alice Springs. Substitution of gasoline by non-sniffable Opal fuel (which is much less likely to cause a "high") has made a difference in some communities.

Elsewhere
In several parts of the world where glue-sniffing is widespread, terms for glue-sniffers have arisen based on brand-names of substances, such as aurolaci in Romania from the brand name Aurolac, or resistoleros in Brazil from the brand name Resistol. These terms are often used even in English-language writing about substance abuse in those regions.

Music and musical culture

 * The Ramones sang "Now I Want to Sniff Some Glue" about adolescent ennui.
 * The punk fanzine "Sniffin' Glue" takes its name from the song but, the fanzine is not about inhalants.
 * In the Nirvana song "Dumb", Kurt Cobain sings "my heart is broke/But I have some glue/ help me inhale /And mend it with you".
 * The Beck song "Fume" from his cassette "Fresh Meat and Old Slabs" is entirely about doing nitrous oxide. He sings: "Had a can of nitrous/we rolled the windows up/Now we're breathing deeply/breathing deeply." The lyrics have a humorous tone throughout, particularly in the chorus: "There's a fume/in this truck/and I don't know if we're dead or what the fuck?"
 * Primus's 1998 song "Lacquer Head" is about adolescents who use inhalants to get high.
 * In the Sum 41 song "Fat Lip", one part of the song is "...you don't make sense from all the gas you be huffing..."
 * The Dead Milkmen song, "Life is Shit" from their album "Beelzebubba" is almost entirely about two friends hallucinating after sniffing glue. The only direct reference is in the first verse, as every verse following it details their hallucinations: "He said 'Yes I do believe this is true, would you like to come and sniff some glue? And we'll fly to where the skies are blue, and look for things both bright and new'".
 * The Eminem song, "Bad Meets Evil" contains the lyric: "I breathe ether in three lethal amounts"
 * The L7 song, "Scrap" is about a skinhead, Scrap, who regularly inhales spraypaint fumes. The first verse describes Scrap thusly: "I met a skinhead named Scrap, he lived in my friend's garage, everyday he's shaking that spraypaint can, and comes out seeing stars," The chorus describes the general use of spraypaint as an inhalant: " Grab a paper bag like an oxygen mask, until your mind starts to gel, because the ball in the can has a crazy beat, the funky dyin' brain cell"

Films and books

 * In the 1996 film Citizen Ruth, the character Ruth sniffs patio sealant from a paper bag.
 * In the movie Love Liza, the main character, played by Philip Seymour Hoffman, develops a gasoline addiction.
 * In the David Lynch film Blue Velvet, Dennis Hopper's character uses a mask to inhale nitrous oxide.
 * In  Little Shop of Horrors, Steve Martin's character dies from nitrous oxide inhalation.
 * In The Cider House Rules, Michael Caine's character is an ether addict.
 * In the film thirteen, the main character uses computer cleaner to get high.
 * Harmony Korine's 1997 film Gummo features two adolescent boys who often huff glue.
 * In the book Fear and Loathing in Las Vegas and in the film version, the two main characters inhale Diethyl Ether and Amyl Nitrite, two of several recreational drugs they take on their trip.
 * In the movie Shooter, Mark Wahlburg inhales gases from a Whip-It! whipped cream canister to knock himself out.
 * In the 1980 Film Airplane!, McCroskey (played by Lloyd Bridges) delivers the famous quote I picked the wrong week to stop sniffing glue.