Barbiturates

 

Medicinal uses

Through the early 1900's barbiturates were prescribed widely for anxiety and insomnia and were also used in conjunction with amphetamines to treat depression. Prescription of barbiturates increased markedly in the late 1950's and 1960's, when up to 500,000 people in the UK were estimated to be taking them, with nearly one quarter of these patients dependent upon them. Their widespread availability resulted in many deaths through accidental overdose and they were a common agent for suicide.

Concern about the addiction potential of barbiturates and the ever-increasing numbers of fatalities associated with them led to the development of alternative medications. With the discovery of a 'safer' alternative - the benzodiazepines - (see Tranquillisers) the medicinal use of barbiturates for treating anxiety and insomnia has been greatly reduced since the 1970's. Nevertheless, phenobarbital is still widely used as an anti-convulsant to control Epilepsy and other barbiturates are occasionally used to treat depression.

 

Abuse of barbiturates

Unlike many other drugs of abuse, barbiturates are rarely produced in clandestine laboratories. Generally, legitimate pharmaceutical products are diverted to the illicit market through forged prescriptions etc., although many barbiturates are also illegally imported from foreign manufacturers.

Barbiturates are generally nicknamed "barbs" or "downers" by drug abusers - or called other names, often based on the color of the capsule, such as "reds" or "yellows". Barbiturates that used to be very commonly abused included amobarbital (Amytal), pentobarbital (Nembutal), and secobarbital (Seconal). As they are not prescribed much these days, these drugs have only a limited presence in the illicit drug market, where they may be available as capsules and tablets or sometimes in a liquid form or suppositories.

Barbiturate sleeping pills are most often abused for their intoxicating effect. Abusers will usually swallow the drug, often with alcohol to increase the inoxicating effect. However, they are also sometimes injected by opening the capsules and dissoving the contents in water. Small particles of undissolved material used as 'bulk' within the capsules can block or damage veins.

 

How do they work?

Barbiturates work by enhancing the action of a brain neurotransmitter (a chemical messenger) that is in charge of inhibiting parts of the brain sometimes. For example, when we go to sleep, some areas of the brain are inhibited, as they are not needed. As barbiturates facilitates the activity of one of the main inhibiting neurotransmitters (Gamma ammino butyric acid - GABA), they have an impact on many aspects of the body including mood, locomotion, co-ordination and even breathing.

 

What effect do they have?

The effects of barbiturates are, in many ways, similar to the effects of alcohol. Small amounts produce calmness and relax muscles. This combination of sedation and reduced anxiety are features which made this type of drug popular as drugs of abuse.

Moderate doses will cause drowsiness, confusion, inability to concentrate, loss of co-ordination, tremors and slurred speech. These effects make it dangerous to drive a car or operate machinery as at these doses judgement is very seriously impaired.

Large doses of barbiturates produce depressed pulse rate, dilated pupils and shallow breathing. As vital life processes (such as heart and breathing rates) may be inhibited, such doses may easily cause unconsciousness and death.

 

Consequences of barbiturate abuse

Consequences for health

Depending on the dose, frequency and duration of use, tolerance and/or physical and psychological dependence on barbiturates can develop very quickly.
As a user becomes tolerant to barbiturates, the margin of safety between an effective dose and a lethal dose becomes very narrow. So to obtain the same level of intoxication, a drug abuser who is tolerant to barbiturates may raise his or her dose to a level that can produce coma and death.
Dependence (or addiction) to barbiturates can occur within a very short time and long-term barbiturate users will require hospitalisation in order to safely undergo the withdrawal effects from such drugs.

Barbiturate overdose is a factor in nearly one-third of all reported drug-related deaths. These include suicides and accidental drug poisonings. Accidental deaths sometimes occur when a user takes one dose, becomes confused and unintentionally takes additional or larger doses. With barbiturates there is less difference between the amount that produces sleep and the amount that kills. Furthermore, barbiturate withdrawal can be more serious than heroin withdrawal.

Legal consequences