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Mirtazapine for depressive disorders


Most of us have had a few days when we find ourselves with low self-esteem, low mood and no desire to do even the activities we like to do. But if those days turn into weeks or even months, what we have is clinical depression.

Although clinical depression is a psychiatric disorder that has been gaining in popularity in the medical field in the last decade, the illness has been recorded and recognised since 1980.

More common in women than in men, and usually appearing in the twenties, the illness can last from months to a lifetime, with episodes of increasing severity. The most widely accepted treatments are both psychological therapy and antidepressants, for example mirtazapine. This is a second-generation antidepressant with such an accepted use that currently in the US alone there are about 6 million prescriptions per year.

 Mirtazapine for depressive disorders

Ok, but what is mirtazapine?

To elaborate a little, mirtazapine is an atypical antidepressant with a tetracyclic structure and classified as noradrenergic and specific serotonergic antidepressants (NaSSA). This last sentence has probably left you more confused than before you read it, so let’s explain it.

Typical antidepressants increase the levels of two neurotransmitters, serotonin and/or noradrenaline. The aim is to improve the patient’s mood and activity by regulating both neurotransmitters. Mirtazapine does this too, but in a different way to other antidepressants (hence ‘atypical’).

It functions as an antagonist for presynaptic adrenergic receptors (presynaptic receptors regulate the release of neurotransmitters, and adrenergic receptors detect noradrenaline), histamine and serotonin. Among all antidepressants, it is the only one that acts in this way.

It is precisely because of the increase in serotonin and noradrenaline levels that it is considered a NaSSA antidepressant.

We say it has a tetracyclic structure because it contains four ring structures.  There is no mystery here. Not everything in science is complicated.

It’s different, but is it better?

What are the benefits of mirtazapine over other drugs? Its atypical status allows it to be effective in cases of clinical depression where typical antidepressants do not work. Mirtazapine is recommended for use in patients with resistance to other drug treatments, sometimes in synergistic use with other drugs.

By itself it has one of the highest yields, showing good results already in the first two weeks. At a normal daily dose, its concentration reaches steady state after four days in adults and six days in older people. For the avoidance of doubt, a steady-state concentration is one in which the amount of drug taken into the body is equal to the amount being excreted, and as with most drugs, it is the liver that is responsible for its degradation.

Another advantage is safety. Side effects are generally mild and transient, such as dry mouth, drowsiness or weight gain in the first few weeks. In contrast to other antidepressants, mirtazapine does not decrease sexual performance or interest, and some studies even claim that it increases interest, an acceptable risk. In studies of one-month pregnant women, mirtazapine has also shown no complications or harm to the mother or embryo. The reported cases where the patient’s health was affected were resolved by the time the treatment was withdrawn.

Although the FDA has only given its approval for the treatment of depression, because of its low side effects it is often used for clinical conditions such as panic disorders, anxiety, post-traumatic stress disorder or even headaches.

But the use where it excels is for sleep. It is common for many of these antidepressants to cause or worsen the insomnia that often accompanies this mood disorder. Mirtazapine has a sedative effect that helps these patients fall asleep. This sedative effect is dose-dependent, increasing at higher concentrations. It is interesting that an a priori negative effect has turned out to be one of its strengths.

Curious about how effective mirtazapine is in your body? With tellmeGen’s Advanced DNA Kit you will find out whether your body is typical or atypical for this drug. Take advantage of the benefits of pharmacogenetic information.