Anxiety and the various problems it can cause in our lives are widely known today. But while it is considered that our current pace of life facilitates the emergence of such problems, the truth is that anxiety is known since ancient times.

Throughout history, attempts have been made to create different techniques and substances effective against anxiety. One of the most successful types of psychotropic drugs until the arrival of benzodiazepines has been barbiturates .

Barbiturates: what are they?

Barbiturates are a type of psychoactive drug , that is, they have calming and depressing effects on the central nervous system. These drugs are derived from barbituric acid, which was first synthesized by Adolf von Baeyer in 1863. However, the first drugs properly known as barbiturates were not introduced until 1903 by Emil Fischer and Josef von Mering. They are considered the first psychopharmaceuticals with sedative-hypnoticals effects.

The action of barbiturates on the nervous system causes a high level of sedation, relaxing and decreasing muscle and mental activity. They have a great effect as a hypnotic, anaesthetic and analgesic . In addition, they are useful in the treatment of seizures and other motor symptoms.

On the other hand, barbiturates generate mood swings , such as mild feelings of euphoria. Because of their effectiveness in reducing anxious symptoms, they were for a time the treatment of choice for symptoms of anxiety, depression and insomnia.

Risks of its consumption

Barbiturates, while highly effective in treating certain symptoms and problems, are highly toxic and have a high level of danger.

Despite their effectiveness, the use of barbiturates poses a high risk to health, easily generating dependency . In addition, the doses that are therapeutic and those that are toxic are very close, which can lead to intoxication and even overdose.

An overdose of barbiturates can result in death in 1 out of 4 cases. In fact, there are many deaths linked to the overdose of these drugs , such as that of Marilyn Monroe.

Today, barbiturates have been superseded by benzodiazepines , which have a higher level of safety, while not generating as much dependence or causing as serious side effects. Despite this, barbiturates are still used medically in specific cases where other substances are not effective, such as anaesthesia in surgical interventions or in neuropsychological examinations (always with a high level of control).

The risks are multiplied if barbiturates are mixed with other substances. In combination with depressants it can cause respiratory failure. Its combination with alcohol, antihistamines and depressant drugs potentiates the depressant effects, and the result can be fatal. On the other hand, taking activating substances in an attempt to counteract the effects of barbiturates can in turn lead to heart problems.

Another risk of great importance is related to pregnant women and nursing mothers . This is because barbiturates, which are highly liposoluble, can be transmitted through the placenta and breast milk. Likewise, an overdose can be dangerous for the life of the foetus, and an abortion can occur.

Some side effects

The consumption of these substances can cause a series of significant side effects , which can even lead to death. Some of these effects may be the following.

1. Excessive sedation

Barbiturates have come to be used as an anesthetic because of their powerful sedative effect. While this can sometimes be sought, it can be detrimental to proper functioning and personal performance by causing excessive sleepiness that reduces an individual’s physical and mental capabilities. They can cause mild paralysis and tingling in different parts of the body.

2. Lack of coordination of different functions

The consumption of barbiturates can cause physical coordination problems, being more complicated to walk or even talk . You should not drive under the effects of this type of medication even if you do not feel sleepy.

3. Cardiorespiratory problems

Barbiturates are powerful psychotropic drugs as depressants of the nervous system, as we have just mentioned. However, this depression can generate respiratory problems, and even in extreme cases there is a risk of cardiorespiratory arrest .

4. Behavioral disinhibition

Although as a rule barbiturates generate depressive effects on the nervous system that sedate the subject, in some people they can produce a high level of behavioural disinhibition, which can lead to the performance of actions that in normal circumstances would not be carried out. In fact, they have been used as supposed “truth serums”.

5. Dependency risk

The addictive potential of this type of substances is very high , generating dependence with great ease. It is also easy to commit abuse in its consumption, which is especially dangerous with this medication. The main reason for this is the high level of tolerance it tends to provoke, which makes it necessary to take more and more to achieve the same effects as in the first doses.

6. Withdrawal syndrome

When a person with a barbiturate dependency stops using them abruptly, they may go into withdrawal. In the case of barbiturate withdrawal, the opposite effects to those of the substance are often generated.

Specifically, it is easy to find restlessness, anxiety, aggressiveness, gastrointestinal symptoms , insomnia , or seizures. Hallucinations and delusions may also occur. It can lead to a drop in blood pressure that is dangerous for survival. In fact, in some cases, withdrawal can be fatal. That is why both the taking and the cessation of the consumption of these drugs must be guided with special caution, withdrawing them gradually.

Mechanism of action

The functioning of barbiturates is mainly based on the facilitation of the action of gamma-aminobutyric acid or GABA, which reduces the overload of the nervous system by making it difficult for nerve impulses to be produced and transmitted.

This enhancement of GABA is carried out by the action of the drug on the ion channels sensitive to this hormone in the brain. Specifically , they make it difficult for sodium to enter the neuron , while at the same time facilitating the entry of chlorine into the cell.

Types of barbiturates

Barbiturates, like other medications, can be classified into several groups depending on how long it takes for them to work and how long the effects last. However, even when the effects end, their characteristics mean that they can remain in the body for a long time. We can identify 4 types of barbiturates .

1. Ultra-short action

The ultra-short acting barbiturates are characterised by a half-life of several minutes , their effects starting seconds after consumption. Within this group we can find thiopental and metohexital.

2. Short action

Those barbiturates such as hexobarbital, pentobarbital or secobarbital are known as short-acting and start their effects between ten and fifteen minutes after consumption to last for about 3 or 4 hours .

3. Intermediate action

Intermediate-acting barbiturates usually take about an hour to take effect, lasting between 6 and 8 hours . Within this type of barbiturate we find one of the most well known and used in various procedures such as the Wada test, the amobarbital.

4. Long action

Primidone and phenobarbital are some examples of long-acting barbiturates, which usually take more than an hour to take effect, but which nevertheless tend to last about 12 hours.

Uses and applications

Although they have now been replaced by other substances in the treatment of most conditions, barbiturates are still used in certain cases. Some of the current or past uses of these substances are reflected below.

Neuropsychological examination

Barbiturates are used in some neuropsychological evaluation procedures. An example of this is the Wada test , in which sodium amobarbital is used to sedate a specific area of the brain and determine the functionality of areas linked to aspects such as laterality, memory or language.


Some barbiturates are used to both initiate and maintain patients under anaesthesia during different surgical procedures. This is one of the main current applications.


One of the indications for certain types of barbiturates is their use in cases where convulsions s appear, as they help to control motor symptoms thanks to their sedative effect and the reinforcement of GABA, which helps to inhibit the discharge of nerve impulses.

Trauma and Stroke

Barbiturates are used to control and diminish the effects of cerebral infarctions , as well as of the edema produced by different cranioencephalic traumas.


While other types of sedatives such as benzodiazepines are currently used, barbiturates have been used in the past as sleeping pills .


As with insomnia, other types of substances (most commonly benzodiazepines and some antidepressants) are now used to treat anxiety, but in the past, barbiturates were the main substance used to treat anxiety .

Bibliographic references:

  • Gómez-Jarabo, G. (1999). Behavioral pharmacology. Basic manual for psychotherapists and clinicians. Madrid: Síntesis psicología.
  • Gómez, M. (2012). Psychobiology. Manual CEDE de Preparación PIR.12. CEDE: Madrid
  • Morón, F.G.; Borroto,R.; Calvo, D.M.; Cires, M.; Cruz, M.A. and Fernández, A. (2009). Clinical pharmacology. Havana: Editorial Ciencias Médicas; 1-30.
  • Salazar, M.; Peralta, C.; Pastor, J. (2011). Manual of Psychopharmacology. Madrid, Editorial Médica Panamericana.