By Razak Hj. Lajis
The Sun, September 21, 1996
VOLATILE SUBSTANCE ABUSE, ALSO known as inhalant abuse, has been reported in medical literature for the past 20 years.
By definition, volatile substances or inhalants are products which give off vapours that can be inhaled to produce intoxicating effects.It is usually accompanied by a change in one's mental state. Glue-sniffing is one of the most common forms of inhalant abuse.
It has been observed that there is an apparent increase in the number of inhalant abuse as a country becomes more industrialised. In developing countries, the problem is said to be encroaching steadily into society.
Many substances requires for industrial purposes and household preparations have become substances of abuse. These include various groups of solvents and aerosol preparations. These substances have volatile hydrocarbons as their base. Examples of hydrocarbons are acetone, benzene, toluene, turpentine and gasoline.
Volatile hydrocarbons can be classified into several groups. They range from high volatility, minimal viscosity substances such as methane, butane, benzene and petroleum ether to minimal volatility, high viscosity products such as lubricating oil, mineral oils and asphalt.
The inhalation of these substances, especially those with high and intermediate volatility, can rapidly displace alveolar gas, causing difficulty in breathing. In addition, they can easily cross the capilary membrane of the lungs and cause central nervous system (CNS) symptoms. Most hydrocarbons are central nervous system depressants and the early effects of inhalation resemble alcohol intoxication.
Continued inhalation of these substances may lead to increased intoxification, leading to confusion, hallucination and aggressive behaviour.
As most of the harmful effects of inhalant abuse are not felt immediately, chronic abuse of inhalants is associated with a variety of medical problems with a real risk of death.
Reports for the last few decades have placed greater concern of inhalant abuse among young people, especially when many inhaled substances are toxic.
The physical form of a product often determines the mode of abuse. Inhalation of chemicals, gases and perfumes is nothing new. In the case of inhalant abuse, compounds are taken indiscriminately through inhalation, a highly effective method to alter moods.
In the old days, people used to smoke and inhale vapours from traditional preparations such as marijuana or cocaine.
Deep inhalation techniques were employed. The effects of the drug may be felt in a few seconds as absorption into the circulatory system is rapid.
There are a number of solvents that have become the target for abuse. A great number of them are known to be toxic (see Table 1).
|Solvent composition of products abused which may produce dangerous toxic effects|
|Products||Major volatile compounds|
|Adhesive/glues||Acetone, Ethyl acetate
|Aerosol Propellants||Liquid Petroleum Gas
|Anaesthetic and analgesics||Nitrous Oxide
Diethylether, halothane, enflurane
|Commercial dry cleaning and degreasing agents||Dichloromethane
|Domestic spot removers and dry cleaners||Dichloromethan
|Fuel Gases||Liquid petroleum gas
|Nail Varnish and nail varnish remover||Acetone and esters|
|Paint and paint thinners||Acetone
|Typewriter correction fluid||Trichlorethane|
The effects of these substances on the body vary greatly among individuals and the type of substances inhaled. The effects would also depend on the amount, duration and frequency of substances inhaled. Once inhaled, the vapours enter the bloodstream rapidly from the lungs. They are then distributed to organs with a large blood circulation such as the brain and liver.
Substances of abuse are deliberately inhaled in order to achieve intoxication. Solvents from contact adhesives, halogenated solvents and volatile hydrocarbons may be abused in this way. These substances will give rise to dose-related effects similar to those of hypnosedatives. Taken in smaller doses, they can cause euphoria, delusions and hallucinations. Higher doses may lead to convulsions and coma.
Chronic abuse of certain substances such as toluene-containing products can produce severe organ damage involving the liver, kidneys and brain. Chronic toxicity is not only related to the compounds abused, but also to the intensity and duration of the abuse. This is obvious as it is almost impossible to assess dosage through repeated breathing and sniffing.
It is often reported that certain types of preparations may be heated to increase the yield of vapours. This is clearly dangerous, especially when it involves petrol, as it will not only produce more vapour, but there is also the risk of fire and explosion as well.
Inhalation of glues remian hazardous and can be fatal. Glues containing n-hexane and toulene have been associated with the development of muscle weakness and atrophy. Three major clinical presentations are common with people who sniff toluene-containing glues. They will experience muscle weakness, gastrointestinal complaints and neuro-psychiatric disorders. Glue sniffers may also develop signs of renal toxicity.
Gasoline or petrol comprise a complex mixture of hydrocarbons have strong narcotic properties and can cause ataxia (uncoordinated movements) and loss of consciousness. The onset of the symptoms occurs with a few minutes of inhalation as there is rapid absoption of the vapours from the lungs.
The euphoria of mild intoxication may be accompanied by nausea and vomiting. Some of the signs and symptoms of acute intoxication are breathing difficulties, chest pain and discomfort, eye irritation, double vision, ringing ears, diarrhoea and muscle and joint pain. After prolonged inhalation or rapid inhalation of highly concentrated vapour, the sniffer may experience a phase of excitement followed by loss of consciousness and coma.
Studies in many countries have shown that many young people may experiment with volatile substance inhalation out of curiosity before getting hooked to it. Although this activity is not regarded as physically addictive, the argument is far from clear.
This is just one of the various common factors that contribute to inhalant abuse. Other factors include peer group influence, lack of parenteral guidance, boredom and availability of ther substances.
It is best not to be argumentative because it will not help us prevent the spread of the problem. The wider availability and high toxicity of some of these substances should stir the need for greater control and preventive action.
Indiscriminate use of volatile substances can be fatal. From 1980 to mid-1987, there were 121 deaths associated with inhalant abuse reported in Australia. Deaths occurred following the abuse of inhalants such as fuel gases, aerosol propellants, petrol and other solvents.
In Britain, the number of deaths recorded over a 20-year span (1971 to 1991) were 1,237 cases. Although the mechanisms of deaths associated with inhalant abuse are not fully understood, most cases involve cardiac failure, anoxia, respiratory depression and vagal inhibition or any combination of the four.
At our home from, there are few cases of inhalant abuse that have been reported. From 1990 to 1994, there were only 63 cases reported.
The majority of inhalant abusers are young people and school children between the ages of 14 and 17. Although the problem is still in its infancy, every effort must be taken to curb this emerging problem.
|The health hazards of some solvents used in substances that are inhaled|
|Solvent||Health hazard summaries|
|Acetone||Vapours mildly irritating to eyes and respiratory tract. A central nervous system depressant at high levels. Ataxia and seizures have been reported|
|Chloroform||Vapours slightly irritating to eyes and respiratory tract. A CNS depressant. Mild to moderate systemic toxicity include headache, nausea, vomiting, confusion and drunkenness. More severe exposures may cause respiratory arrest and coma. A carcinogen in animals.|
|n-Hexane||Vapours mildly irritating to eyes and respiratory tract. Light-headedness, giddiness, nausea and headache. Greater exposure may cause unconsciousness and death.|
|Toluene||Acute exposure results in euphoria, excitement, dizziness, headache, nervousness, ataxia, convulsion and coma. Deaths have been recorded from acute exposure to toluene in "sniffers."|
|Trichloroethane||A respiratory and CNS depressant. The symptoms of acute inhalation may include nausea, euphoria, ataxia, dizziness, agitation and lethargy. Severe exposure will lead to respiratory arrest, seizures and coma|
|Xylene||Dizziness, excitement, flushing of the face, drowsiness, incoordination, tremor, confusion, respiratory depression and coma|
The writer is a pharmacist at the National Poison Centre, Universiti Sains Malaysia, Penang.