What is the use of mirtazapine (Remeron)?

From the Guidelines

Mirtazapine is recommended as a viable treatment option for major depressive disorder, particularly in patients with sleep disturbances and poor appetite, due to its unique mechanism of action and sedating properties. Mirtazapine works by affecting both norepinephrine and serotonin systems through antagonism of specific receptors (alpha-2 adrenergic receptors and certain serotonin receptors) 1. This contributes to its effectiveness for depression, as it has sedating and appetite-stimulating properties.

Some key points to consider when prescribing mirtazapine include:

• Typical dosing ranges from 15 to 45 mg taken once daily at bedtime, with treatment usually beginning at a lower dose (15 mg) and may be gradually increased based on response and tolerability 2.
• Common side effects include drowsiness, increased appetite, weight gain, and dry mouth, with sedating effects being stronger at lower doses (15 mg) and may decrease at higher doses 3.
• Patients should be aware that improvement in depression symptoms may take several weeks, though sleep improvements often occur sooner 4.
• Mirtazapine should not be abruptly discontinued after long-term use but rather tapered gradually under medical supervision to avoid withdrawal symptoms 5.

It's also important to note that mirtazapine has a faster onset of action compared to some other antidepressants, such as fluoxetine, paroxetine, or sertraline 1. However, the response rates of mirtazapine and venlafaxine did not differ significantly 1.

In terms of safety and efficacy, mirtazapine is generally well-tolerated, but patients should be cautioned about the potential for adverse effects, such as increased appetite and weight gain 2. Additionally, mirtazapine may be associated with an increased risk for certain adverse events, such as somnolence and dry mouth 3.

Overall, mirtazapine is a viable treatment option for major depressive disorder, particularly in patients with sleep disturbances and poor appetite, due to its unique mechanism of action and sedating properties. However, patients should be closely monitored for potential adverse effects and response to treatment.

From the FDA Drug Label

Mirtazapine tablets are indicated for the treatment of major depressive disorder (MDD) in adults [see Clinical Studies (14)]. Mirtazapine is used for the treatment of major depressive disorder (MDD) in adults.

• The indication is specifically for adults with MDD. 6

From the Research

Overview of Mirtazapine

• Mirtazapine is an antidepressant that blocks presynaptic alpha 2-adrenergic receptors and postsynaptic serotonin type 2 and type 3 receptors 7.
• It has FDA-approved labeling for the treatment of depression and may also have beneficial anxiolytic and sedative effects 7.
• Mirtazapine is rapidly and completely absorbed after oral administration and is biotransformed by hepatic demethylation, making it suitable for once-daily doses 7.

Efficacy of Mirtazapine

• Mirtazapine has been shown to be equally efficacious as amitriptyline, clomipramine, and doxepin in the treatment of depression 7, 8.
• It has a novel mechanism of action, increasing noradrenergic and serotonergic neurotransmission via blockade of central α2-adrenergic auto- and heteroreceptors 8.
• Mirtazapine may also be effective in the treatment of anxiety disorders, obsessive-compulsive disorder, and undifferentiated somatoform disorder 9.

Tolerability and Safety of Mirtazapine

• Mirtazapine is generally well tolerated, with the most commonly reported adverse effects being somnolence, increased appetite, weight gain, and dizziness 7, 8.
• It has a lower propensity for inducing seizures and is safe in overdose 8.
• Mirtazapine may have a more favorable side-effect profile compared to selective serotonin reuptake inhibitors (SSRIs), with fewer reports of insomnia, nausea, and sexual dysfunction 10.

Dosage and Administration of Mirtazapine

• The recommended starting dosage of mirtazapine is 15 mg/day, which can be increased to 30 mg/day after 4 days and further increased to 45 mg/day if necessary 8, 11.
• The optimal dose of mirtazapine for the treatment of major depression is around 30 mg/day, with higher doses showing decreased efficacy 11.