The Mirtazapine Side Effects

mirtazapine side effectsMirtazapine is a tetracyclic anti-depressive drug, prescribed specially for the treatment and management of major depression and mood disorders. Since it is a noradrenergic and specific serotonergic antidepressant, it’s much more tolerable in terms of side effects, and rather superior to most serotonin-norepinephrine reuptake inhibitors and selective serotonin reuptake inhibitors.

Mirtazapine also has an appetite stimulatory effect, it’s also an anxiolytic and hypnotic drug, that’s why it’s often prescribed off-label for the treatment and management of various diseases and conditions like: mood disorders, panic disorder, insomnia, anorexia nervosa, low appetite, various types of anxiety, posttraumatic stress, obsessive-compulsive disorder and even headaches and migraines.

Although compared with other antidepressants, mirtazapine side effects are more tolerable, but that doesn’t mean they are inexistent. Some of the most common mirtazapine side effects are: lethargy, somnolence, lack of motivation for anything, increased appetite and constipation. Due to the fact that this drug increases appetite, this being one of the effects it is actually recommended for, one of the mirtazapine side effects can be weight gain.

Usually the most common mirtazapine side effects associated with higher dosage, although rarer than the ones mentioned above, are: aggression, restlessness, difficulties breathing and swallowing, dry mouth and a severe state of malaise.

Patients on medication with mirtazapine may also experience various adverse effects of sexual nature. These are: spontaneous orgasms, nocturnal emissions or sexual anhedonia.

Some of the very rare adverse effects associated with the intake of mirtazapine are: seizures, agranulocytosis (lowered blood level of white blood cells), myelodysplasia (low production of myeloid class cells), bone marrow suppression and seizures.

Finally, although rare allergic reactions have been reported as mirtazapine side effects, these aren’t excluded from the list. They can take the form of skin rashed, edema, anaphylaxis.

In general, for all the drugs that may cause withdrawal symptoms, a slow and gradual reduction of the dose is recommended to avoid or minimize the withdrawal effect. Some of the mirtazapine side effects that may occur due to abrupt cessation are: panic attacks, anxiety, aggression, restlessness, insomnia, gastrointestinal problems (vomiting, nausea, diarrhea), mood changes, skin itchiness, headaches, and lack of appetite.

Mirtazapine should not be administered with CYP P450, CYP1A2, CYP3A4 inhibitors (fluoxetine, paroxetine, amentoflavone, rhapontigenin, epsilon-viniferin). These are the enzymes that are responsible for the metabolization process of mirtazapine, and once blocked or slowed, it might lead to high blood levels of the drug.

It’s been speculated that mirtazapine should not been administered along with MAOI drugs due to an increased risk of serotonin toxicity. However, recent studies have shown that there aren’t any serotonin toxicity related risks if mertazapine is administered in conjunction with MAOI drugs.

Lastly, in patients with renal and liver problems, the oral clearance of mirtazapine may be impaired. So, it’s not recommended to patients with conditions of this nature. Also, in conjunction with some antihypertensive drugs, like clonidine, one of the mirtazapine side effects may be hypertension.

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