Barbiturates, types and side effects

Barbiturates, types and side effects

Barbiturates are a class of psychoactive substances derived from barbituric acid that act as central nervous system (CNS) depressants. They produce sedative effects and are effective as anxiolytics, hypnotics and anticonvulsants (to treat epilepsy).

They are very dangerous since there is no effective treatment to reverse an overdose of barbiturates, it is for this reason that they were used for a long time as anxiolytics and hypnotics between the 60s and 70s, but today they have been replaced by benzodiazepines, which are less toxic in case of overdose. However, barbiturates are still used as anticonvulsants (e.g., Phenobarbital and primidone) and general anesthesia.

Other uses of barbiturates in the 21st century are suicide assisted by doctors (in countries and states where this procedure is legal), and as lethal injection in convicts in the US. They are also frequently used as euthanasia agents in veterinary medicine.


  • 1 Operation of barbiturates
  • 2 side effects
  • 3 Types of barbiturates

How barbiturates work

Barbiturates, as we have said, are central nervous system depressants. They act by improving the action of GABA, a neurotransmitter It inhibits the activity of nerve cells in the brain.

The Thiopental or Thiopentate Sodium is an ultra-short-acting barbiturate that is marketed under the name of pentotal sodium, sodium amital or trapanal. It is classified as ultra-short-acting barbiturate because the hypnotic effect in small doses of the drug disappears in a few minutes. Currently little is used due to the slow and heavy recovery of the patient. He was the first barbiturate introduced as an inducing agent in surgery in 1934 given his rapid effect as an anesthesia inducer. Also, it has been used to induce medical coma states, to decrease brain metabolic requirements. Together with metohexital, it is the most commonly used barbiturate in clinical anesthesia.

The serum of truth

As a curiosity the pentothal It has been used historically in psychiatry since it seemed to improve the fluidity of the patient's response. This is the use that has given fame to this drug, and for what is known as truth serum. In controlled doses, its hypnotic performance in the human brain produces depression of superior cortical functions, which suggested that it could be useful in interrogations. The lie It is considered to be a complex, conscious elaboration, much more complicated than the truth, so if the superior cortical activity deteriorates, the subject may find it much more complicated to maintain his will and supposedly tend to say the "truth." That is, at least, the theory, and that is why it has been put into practice for decades by the spy services of many countries. To some extent, the idea is correct, but does not guarantee, much less, that the subject will tell what is expected, since there are many factors that can modify the results, from a special training to environmental conditions or, simply, an assumption of the lie as truth.

It may interest you: 10 ways to catch a liar

On the other hand, it is also believed Thiopental-induced memory and cognitive impairment reduce a subject's ability to invent and remember lies. This practice is no longer considered legally admissible because of the findings that subjects subjected to such interrogations may form false memories, calling into question the reliability of all information obtained through such methods. However, it is still used in certain circumstances by defense and law enforcement agencies as a "human" alternative to the interrogation of torture when it is believed that the subject possesses critical information for the security of the state or agency that employs the tactic .

Side effects

The pharmacological actions of barbiturates include depression of nerve activity in the heart, smooth and skeletal muscles. Barbiturates also affect the central nervous system in different ways and can produce effects ranging from mild sedation to coma, depending on the dose.

Low doses of barbiturates may decrease anxiety levels and relieve tension, while higher doses may decrease heart rate and blood pressure.

Barbiturates can be considered extremely addictive from the physical and psychological point of view. Short-acting barbiturates are significantly more addictive than longer-acting barbiturates.

Barbiturate overdose

Symptoms of an overdose of barbiturates include severe mental deceleration, difficulty speaking, confusion, delusions, respiratory depression, coma and death.

It is worth noting that Sudden interruption of barbiturates can be very dangerous and endanger the lives of people who consume regularly for prolonged periods of time, which sometimes causes seizures or even death, so it must be done in sufficiently prepared clinical centers.

Types of barbiturates


Commonly known as "sodium amital" or "sodium pentothal", this barbiturate is the one that earned the reputation of being the real serum. While it doesn't really force people to tell the truth, amobarbital can slow down the central nervous system so that concentration becomes more difficult. The theory was that someone asked a question while, under the influence of amobarbital, they would be less likely to think of a false answer, which requires more attention than simply telling the truth.


This short-acting barbiturate is often used for treat migraine headaches, often in combination with paracetamol, aspirin and caffeine. It has also been used as a sedative and anesthetic.


This barbiturate was used to treat seizures in children, due to its anticonvulsant function. It has also been used to treat anxiety, drug withdrawal (particularly from other barbiturates) and as a sleep aid.


Marketed in the USA UU. As a Seconal from 1934, this drug was prescribed for many years to combat insomnia. It is the most used drug in suicides assisted by doctors in that country.


Used as an anesthetic in animals, this medicine was used in the past to treat seizures and seizures. It also has the dubious distinction of being one of the preferred drugs for executions of prisoners in the United States.


Sota Omoigui's Anesthesia Drugs Handbook. Jack Omoigui. Editorial State-Of-The-Art Technologies Inc, Third Edition