Solvent abuse has become a common problem, particularly in teenagers who inhale volatile organic solvents such as toluene in glues (‘glue sniffing’). Many other solvents, such as aerosols (hair lacquer), antifreeze and petrol, can also be misused. Solvents are applied to a piece of cloth or put into a plastic bag and inhaled, often until consciousness is lost. The patient presents either in the acute intoxicated state or as a chronic abuser with excoriation and rashes over the face and a peripheral neuropathy. Sudden death can occur and is probably due to cardiac arrhythmias. Stigmata of solvent abuse include sores or a rash around the nose and mouth and glue on the clothing.
Drug addicts frequently overdose themselves and are commonly admitted to hospital with the signs of opiate injection. Tell-tale injection sites and pin-point pupils are important clues. Naloxone is given in the same dosage as for co-proxamol overdose.
Cannabis is usually smoked and often taken casually. Initially there is euphoria, followed by drowsiness and sleep. Redness of the conjunctivae and pupil dilatation are seen. No specific treatment is required.
Amphetamines are taken for their stimulatory effect. In overdose there is confusion, delirium, hallucinations and violent behaviour. Cardiac arrhythmias can be a major problem. Treatment is with sedatives, such as diazepam. Forced acid diuresis may be used but is rarely required.
Cocaine can be taken by injection, inhalation or ingestion. It produces excitement, over-alertness, euphoria and restlessness. This is followed by delirium, tremor, convulsions, pyrexia and cardiac arrhythmias, which may cause cardiac failure. Respiratory failure may also occur. Treatment is symptomatic and supportive. There is no specific antidote. 13-Blockers should not be used to treat hypertension or tachycardia.
This drug is also known as MDMA (3,4- methylenedioxymethamphetamine) and is a semisynthetic hallucinogenic drug whose initial effects are sympathomimetic and may cause tachyarrhythmias, hyperpyrexia, clonic movements and convulsions, coagulopathy, rhabdomyolysis and renal failure. Treatment consists of gastric lavage, chlorpromazine, a- and J3-adrenergic blockade, intravenous fluids and passive cooling.