Remeron
Meaning of Remeron: Drowsiness and a bigger appetite come from strong histamine blockade, side effects that are sometimes the reason it is chosen.
Definition of Remeron
Remeron is a brand name for mirtazapine, an antidepressant. Unlike the reuptake inhibitors that dominate the field, mirtazapine does not block the pumps that draw serotonin and norepinephrine back into nerve cells. It blocks receptors instead, lifting a brake on the release of both messengers while switching off several other receptor types along the way.
How does it work differently from an SSRI?
| Mirtazapine | SSRI | |
|---|---|---|
| Main action | Blocks receptors that normally restrain release | Blocks the pump that recycles serotonin |
| Messengers affected | Serotonin and norepinephrine | Serotonin |
| Typical effect on sleep | Sedating | Often activating, sometimes disrupts sleep |
| Typical effect on weight | Appetite and weight tend to rise | Variable, often neutral early on |
| Nausea and sexual effects | Comparatively uncommon | Common early, sexual effects may persist |
The receptors mirtazapine blocks include the ones that would otherwise damp down nerve cell firing, so both messengers are released more freely. It also blocks two serotonin receptor subtypes tied to nausea and to restlessness, which is why those complaints are less prominent than with an antidepressant that raises serotonin indiscriminately.
Why does it cause drowsiness and appetite gain?
Mirtazapine is a strong blocker of histamine receptors in the brain, the same action behind the sleepiness of older allergy medicines. That accounts for the sedation, which is often most noticeable in the first days of treatment, and it contributes along with the serotonin receptor blockade to increased appetite and weight gain. These effects are sometimes the point rather than a nuisance, since depression that has brought poor sleep and lost weight leaves a particular gap that this profile fills.
How is it used in practice?
The mood effects build gradually, over weeks rather than days, in common with other antidepressants, while the sedative effect appears at once. It is taken by mouth, including a form that dissolves on the tongue, and it may be used alone or added to another antidepressant when a partial response has stalled. Abrupt discontinuation after prolonged use can produce withdrawal symptoms, so courses are normally brought to an end gradually.
Also known as
Used in a sentence
Remeron was prescribed for the patient's depression, in part because of associated sleep disturbance.
Good to know
Mirtazapine increases appetite and causes drowsiness through histamine receptor blockade, a side effect profile quite unlike that of the selective serotonin reuptake inhibitors and one that sometimes influences which antidepressant is selected.