What are Barbiturates

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. Barbiturates 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.

History of Barbiturates
Barbiturates 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 pharamaceutical company), discovered that barbital was very effective as a sedative when they conducted experiments on dog. In 1912, Bayer launched phenobarbital, which was another barbituric acid derivative under the trade name Luminal, as a sedative-hypnotic.

Classification of Barbiturates
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' in emergency surgery situations. The middle two classes of barbiturates are short or intermediate-acting. These barbiturates are used for anesthetic purposes as well as to cure anxiety or insomnia. They have now been replaced by benzodiazepines. The last class of barbiturates consists of long-acting barbiturates. This class of barbiturates are used exclusively for treating convulsions, although on certain occasions they may be prescribed for sedation during daytime. Barbiturates of this class are never recommended for insomnia due to their extremely long half-life.

Effects of Barbiturates 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 barbiturates clear out of the blood stream varies for different barbiturates.

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.

Therapeutic Uses of Barbiturates
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.

Behavioral Effects of Barbiturates
Barbiturates have several effects on human behavior depending on the dosage:

• In low doses, barbiturates reduce anxiety, respiration, blood pressure, heart rate and rapid eye movement (REM).
• In higher doses, barbiturates can stimulate certain types of behavior and suppress inhibitions.
• Overdose of barbiturates 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 for barbiturates include:

• Anxiety
• Insomnia
• Seizures
• Nausea
• Stomach Problems
• Hallucinations

Drug Abuse
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 barbiturates. Amobarbital (Amytal), pentobarbital (Nembutal) and secobarbital (Seconal) are the commonly abused barbiturates. The problems associated with acute barbiturate abuse are respiratory disorders, depression and physical or psychological dependence. Other effects of barbiturate 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. Use of barbiturates for medicinal purpose should be done only with a proper prescription from a physician. Illegal transportation or possession of barbiturates can land you in trouble.