Phenelzine: uses, risks and side effects of this antidepressant

Currently, antidepressants are used worldwide to treat especially depression. This use has increased over the years, although at first only MAOIs (monoamine oxidase inhibitors) were used, the first antidepressants to be synthesized.

Here We will know about phenelzine, an antidepressant from the MAOI group. We are going to see how it works, its most important characteristics, as well as its therapeutic indications.

• Related article: "Types of psychoactive drugs: uses and side effects"

As we have seen, phenelzine is an antidepressant that belongs to the group of monoamine oxidase inhibitors (MAOI). It is a non-selective MAOI, that is, it inhibits both type A and type B monoamine oxidases. Monoamine oxidases are enzymes that break down the neurotransmitters -amines (serotonin and norepinephrine).

Phenelzine is considered the first commercially available antidepressant. On the other hand, although MAOIs have been replaced by other more modern drugs in most cases, their pharmacological action means that they continue to be the most effective in

treatment of atypical depressions, for example. It is also effective in those cases where other medications have not produced results, and in intense anxiety.

Phenelzine is available as a tablet to be taken by mouth.

• You may be interested in: "MAOIs (monoamine oxidase inhibitors): effects and types"

Mechanism of action

This antidepressant works by increase the amount of certain natural substances that are necessary to maintain mental balance. Specifically, they work by blocking the action of the enzyme monoamine oxidase. Said enzyme degrades serotonin and norepinephrine; when it is degraded, its action is interrupted, and therefore the amount of serotonin (SA) and norepinephrine (NA) in the brain increases.

Both SA and NA have been directly related to depression; people with depression often have lower levels of these neurotransmitters.

Therapeutic indications

Phenelzine is mainly used to treat depression in people who have not responded to other medicines, such as in atypical depression (whose symptoms are hypersomnia, hypersensitivity, increased appetite, extreme tiredness and marked anxiety).

On the other hand, It is also indicated for anxiety, bulimia and social phobia.

Side effects

Some of the side or adverse effects of phenelzine are:

• Drowsiness (dream).
• Weakness.
• Dizziness.
• Dry mouth.
• Constipation.
• Weight gain.
• Decreased sexual ability.
• uncontrollable shaking of a part of the body.
• Stiffness or muscle spasms.

Suicidal tendencies with this drug

It should be noted that during clinical studies of phenelzine, a small number of children, adolescents, and young adults (up to 24 years of age) who took antidepressants such as phenelzine had tendencies suicidal. These were translated into thoughts such as harming or committing suicide, planning to do it or trying to do it.

These suicidal tendencies appeared in both phenelzine and many other antidepressants. Thus, it is known that children, adolescents, and young adults who take antidepressants to treat depression or other disorders are more likely to have suicidal thoughts than those who do not take antidepressants to treat such conditions.

However, experts do not know exactly what the risk of taking it is, nor to what extent should we consider this probability of the appearance of suicidal tendencies in the case of a child or adolescent who must take antidepressants.

However, children under 18 years of age should not take phenelzine regularly, although in some cases, the doctor may decide that phenelzine is the best option.

Bibliographic references:

• phenelzine. NIH MedlinePlus Health [Internet]. 2017; Available from: https://medlineplus.gov/spanish/druginfo/meds/a682089-es.html. Spanish English.
• www.vademecum.es.
• www.psicologiaymente.com.