Barbiturates are drugs that act as depressants for the central nervous system and produce a wide range of effects from mild sedation to anesthesia. People show a strong physical and psychological addiction to them. These are also used for therapeutic purposes. Read on to know more.
Life has become very hectic and stressful in today’s world. Many people cannot cope with the mounting stress and often resort to alcohol and drugs. More and more people are falling prey to insomnia and have started abusing a class of drugs called barbiturates. These are drugs that induce sleep and a feeling of calm. In medical terms, barbiturates are medicines that act on the central nervous system, cause drowsiness and can control convulsions.
They are basically derivatives of barbituric acid. Barbituric acid was first synthesized on December 6, 1864, by German scientist Adolf Von Baeyer. This was done by condensing urea and diethyl malonate – an ester derived from the acid of apples. Barbituric acid itself does not induce any effect on the central nervous system, but there are over 2,500 barbiturate compounds that possess pharmacological properties. Medicinal properties of barbiturates were not discovered until 1903. In 1903, two German chemists Emil Fischer and Joseph von Mering working at Bayer (a pharmaceutical company), discovered that barbital was very effective as a sedative when they conducted experiments on a dog. In 1912, Bayer launched phenobarbital, which was another barbituric acid derivative under the trade name Luminal, as a sedative-hypnotic.
The broad class of barbiturates is classified according to their speed of onset and duration of action. Ultrashort-acting barbiturates are used in the medical field for anesthetic purposes. Their short span of action is extremely helpful for doctors to rapidly put a patient ‘under’ it, in case of situations that arise during emergency surgeries. The middle two classes of barbiturates are short or intermediate-acting. These are used for anesthetic purposes as well as to cure anxiety or insomnia. They have now been replaced by benzodiazepines. The last class consists of long-acting barbiturates. These are used exclusively for treating convulsions, although on certain occasions they may be prescribed for sedation during daytime. Drugs belonging to this class are never recommended for insomnia due to their extremely long half-life.
Effects on the Brain
Barbiturates are soluble in body fat. Hence, they can easily find their way to the brain by crossing the blood-brain barrier. Also, they can accumulate within the blood stream and re-enter it. The rate at which they clear out of the blood stream varies for different drugs.
Although the exact mechanism by which barbiturates affect the brain is yet unknown, it is assumed that these drugs bind to sodium channels on neurons and obstruct the flow of sodium ions. This results in the reduction of the action potential. Barbiturates are also responsible for increasing the flow of chloride ions across the neuronal membrane. The chloride ions bind to the receptor of the neurotransmitter called GABA. The increased chloride ion flow reduces the chances of generation of action potential.
Barbiturates like pentobarbital and phenobarbital were earlier used as anxiolytics and hypnotics, but have now been replaced with benzodiazepines. An overdose of benzodiazepines has less potential for producing fatal effects. Pentothal and other ultrashort-acting barbiturates are mostly used in hospital settings as they are not likely to be abused. Phenobarbital is a useful anticonvulsant for people suffering from seizure disorders such as febrile seizures, tonic-clonic seizures, status epilepticus, and eclampsia.
Barbiturates have several effects on human behavior depending on the dosage:
- In low doses, they reduce anxiety, respiration, blood pressure, heart rate and rapid eye movement (REM).
- In higher doses, they can stimulate certain types of behavior and suppress inhibitions.
- Overdose can lead to excessive sedation and cause anesthesia, coma and even death.
A major concern with barbiturates is that they may lead to tolerance and dependence. Tolerance is a condition when a greater amount of the drug is required to get the desired effect. Dependence results when a person finds it difficult to live without the influence of the drug.
When a person stops using the drug it results in withdrawal symptoms. Withdrawal symptoms include:
- Stomach Problems
Most people using barbiturates report that a barbiturate ‘high’ gives them a feeling of ecstasy or relaxed contentment or euphoria. Drug addicts tend to prefer short-acting and intermediate-acting drugs. Amobarbital (Amytal), pentobarbital (Nembutal) and secobarbital (Seconal) are the most commonly abused. The problems associated with acute barbiturate abuse are respiratory disorders, depression and physical or psychological dependence. Other effects of its intoxication are drowsiness, lateral and vertical nystagmus, slurred speech and ataxia, decreased anxiety, loss of inhibition, etc.
Thus, one should avoid unnecessary consumption of barbiturates. Their use for medicinal purpose should be done only with a proper prescription from a physician. Illegal transportation or possession of these drugs can land you in trouble.