This type of drug is prescribed to combat episodes of anxiety.
When a person has anxiety and resorts to drug treatment, they are likely to be prescribed an anxiolytic.
Anxiolytics are drugs that have been used for many years to reduce anxiety levels and induce a state of relaxation in the person.
In this article we will learn about the four main types of anxiolytics that exist, according to their properties and indications. We will know what each group is indicated for, what its mechanism of action is, characteristics, side effects and differences between them.
Types of anxiolytics
Anxiolytics are drugs used to reduce anxiety levels. Thus, they are especially indicated for anxiety disorders, although they also present other indications .
In other words, they are used for anxiety disorders, but also for different conditions that are accompanied by an anxious component (for example, a depressive disorder with anxious symptoms, an adjustment disorder…).
- Related article: “Types of antidepressants: uses, indications and side effects”
There are different types of anxiolytics, according to their properties, mechanism of action, indications, side effects… We are going to see the characteristics of the four large groups and the differences that we find between them.
1. Barbiturates
The first anxiolytic drugs to be marketed were barbiturates ; these drugs derive from barbituric acid, and produce drowsiness and sedation, since they depress the Central Nervous System (CNS).
They were first used to treat anxious symptoms and cause relaxation. However, they were later superseded by benzodiazepines, since barbiturates were not very safe (they easily overdosed). In fact, barbiturates were used in the United States for the execution of people sentenced to death (as part of lethal injection).
Currently, barbiturates are not used for anxiety, and instead are used as antiepileptics (for example, phenobarbital and primidone). In underdeveloped countries, moreover, phenobarbital is the only antiepileptic drug available. This in particular is the most prescribed barbiturate in the world.
2. Benzodiazepines
Continuing with the types of anxiolytics, we find the anxiolytics after the barbiturates: the benzodiazepines. Their mechanism of action is as follows: they are indirect agonists of the GABA A receptor that act on the cortex and the limbic system.
That is, what benzodiazepines do is increase the concentration of GABA in the brain ; GABA is the quintessential depressant neurotransmitter. That is why an increase in its concentration leads to relaxing effects. Benzodiazepines are also used as muscle relaxants, not just anxiolytics.
Use
Although benzodiazepines were the “star” anxiolytics for many years, and were used in many cases, they are currently not drugs of choice for any anxiety disorder. They are still used, yes, but often inappropriately, since it was observed that they were highly addictive drugs, which created dependence in patients.
It is paradoxical that even knowing all this, benzodiazepines are currently the most prescribed psychotropic drugs as anxiolytic drugs.
It is for all of the above, so they should be used with great caution and always under medical prescription; Ideally, they should be used for a certain time, but not for many months. This at the moment of truth is not real, since there are many people who have been taking them for years.
Indications
Having said that, let’s get to know the indications for benzodiazepines: they are prescribed for anxiety disorders, such as Generalized Anxiety Disorder (GAD), Panic Disorder (PD), Social Phobia (SF) and adjustment disorders.
On the other hand, due to their pharmacological properties, they are types of anxiolytics also indicated for depression (especially alprazolam) and insomnia (triazolam and tepazepam). Finally, they are also used for Bipolar Disorder (BD) (clonazepam) and alcohol withdrawal.
Classification
These types of anxiolytics, in turn, are classified into subtypes based on their half-life . The half-life (or action) of a drug means how long it takes for it to be metabolized by half, that is, it is a parameter that contemplates the drug’s action time.
Thus, the shorter the half-life, the faster the drug acts in the body. In other words, short-acting benzodiazepines produce their effect more immediately than medium- or long-acting ones, which produce it over a longer period of time. This means that the effect of long-acting benzodiazepines lasts longer than the other types.
In this way, we find benzodiazepines of three types: short half-life (or short action), medium or intermediate half-life (or medium action) and long half-life (or long action). Let’s see examples and characteristics of each:
1. Short Action
Examples of short-lived benzodiazepines are: triazolam, midazolam, bentazepam, brotizolam… As characteristics, we know that short-lived benzodiazepines are the ones that create more dependency (compared to those with medium and/or long life). In addition, they are the ones with the most side effects.
2. Medium Action
We find half-life benzodiazepines: alprazolam, lorazepam, bromazepam, oxazepam… This second type has an “intermediate” number of side effects between short-acting and long-acting.
3. Long action
Finally, long-acting benzodiazepines are, for example: clonazepam, diazepam, flurazepam, medazepam… These have a lower risk of dependence; on the other hand, they present a risk of daytime sedation (since their effects last longer; they are the most “potent”).
Side effects
Regarding the side effects of these types of anxiolytics, benzodiazepines can cause: risk of addiction, withdrawal syndrome (anxiety, rebound insomnia…), memory impairment (recall difficulties, anterograde amnesia…), as well as attentional difficulties and in performance (slowing).
As adverse reactions we found a paradoxical reaction in the elderly.
3. Serotonergic anxiolytics
Serotonergic anxiolytics, other types of anxiolytics, consist of partial agonists of a serotonin receptor (5-HT1A). This means that they increase the concentration of serotonin in the brain, a neurotransmitter related to mood. Unlike benzodiazepines, serotonergic anxiolytics do not interact with GABA.
As a typical example of this group we find buspirone (commercial names: Ansial or Buspar). Buspirone is the pharmacological treatment of choice for Generalized Anxiety Disorder (GAD). For GAD, in addition, venlafaxine (a 4th generation antidepressant) is also considered the drug of choice.
As advantages of this type of anxiolytics, we have that they do not create addiction and that they do not interact with alcohol, as other types of anxiolytics do. As disadvantages, we find a delay in its effect.
Indications
They are indicated for GAD and to treat anxiety in substance abuse and alcoholism (by not interacting with alcohol).
4. Short-acting non-benzodiazepine hypnotics
As a fourth group of types of anxiolytics, we find this type of hypnotics , indicated to treat insomnia. They are easy to memorize because they all start with “Z”: zaleplon, zolpidem, and zoplicone. These are GABA agonists, which act only in regions where they induce sleep.
Like the benzodiazepines, these types of anxiolytics can be classified according to their half-lives: thus, zaleplon and zolpidem have a short half-life, and zoplicone has a long half-life. The advantage of this group of anxiolytics is that they have fewer side effects than benzodiazepines.
Final considerations
Although anxiolytics are the “par excellence” drugs to treat different anxiety disorders, antidepressants are another group of drugs that also have anxiolytic properties , and therefore are also indicated to treat this type of condition.
Everything will depend on the diagnosis of each patient, their needs and personal characteristics. However, we must remember that a psychopharmacological treatment should always be accompanied by a psychological treatment.
Bibliographic references
- Lopez, J.M. (2019). History of barbiturates. Pharmaceutical reviews, Info-farmacia.com.
- Stahl, SM (2002). Essential psychopharmacology. Neuroscientific bases and clinical applications. Barcelona: Ariel.
To the classic question “what do you do?” I always answer “basically I am a psychologist”. In fact, my academic training has revolved around the psychology of development, education and community, a field of study influenced my volunteer activities, as well as my first work experiences in personal services.