Generic

Mirtazapine

Indications

Mirtazapine Tablets are used to treat major depressive disorder (MDD) (MDD).

Pharmacology

Pharmacodynamics: Mirtazapine’s mechanism of action, like those of other medications used to treat severe depressive illness, remains unclear. Mirtazapine appears to boost central noradrenergic and serotonergic activity, according to evidence obtained in preclinical investigations. Mirtazapine works as an antagonist at central presynaptic 2-adrenergic inhibitory autoreceptors and heteroreceptors, resulting in an increase in central noradrenergic and serotonergic activity, according to these findings. Mirtazapine is a powerful 5-HT2 and 5-HT3 receptor antagonist. The 5-HT1A and 5-HT1B receptors have no appreciable affinity for mirtazapine. Mirtazapine is a strong antagonist of histamine (H1) receptors, which may account for its sedative properties. Mirtazapine is a moderate peripheral 1-adrenergic antagonist, which might explain the orthostatic hypotension that has been recorded in patients using it.

Mirtazapine is a moderate antagonist at muscarinic receptors, a property that may explain the relatively low incidence of anticholinergic side effects associated with its use. Pharmacokinetics: After oral administration of Mirtazapine tablets, the active constituent mirtazapine is rapidly and well-absorbed, reaching peak plasma levels after about 2 hours. Binding of mirtazapine to plasma proteins is approximately 85%. The mean half-life of elimination is 20-40 hours; (26 hours in males, 37 hours in females).

Dosage & Administration

Adult dose: The recommended starting dose for Mirtazapine tablets is 15 mg/day, administered in a single dose, preferably in the evening or prior to sleep. The effective dose range was generally 15 to 45 mg/day and the patients not responding to the initial 15 mg dose may benefit from dose increases up to a 30 mg to maximum of 45 mg/day. Mirtazapine has an elimination half-life of approximately 20 to 40 hours; therefore, dose changes should be made at intervals of less than 1 to 2 weeks in order to allow sufficient time for the therapeutic response to a given dose.

Use in children: Use in children are not recommended to Mirtazapine.

Missed Dose: If anyone misses a dose of mirtazapine, take it as soon as remember unless it is close to when the next dose is due. If anyone missed a dose of medication and it is close to the time of next dose, skip the missed dose and should take next dose at the regularly scheduled time. One should not take double or more than prescribed dose.

Interaction

Monoamine Oxidase Inhibitors (MAOI) and other serotonergic medications such as tryptophan, triptans, linezolid, serotonin reuptake inhibitors, venlafaxine, lithium, tramadol, or St. John’s wort have clinically significant drug-drug interactions with mirtazapine. Carbamazepine, Phenytoin, and Cimetidine’s metabolism and action may be disrupted by Mirtazapine. When using Mirtazapine, the patient should avoid drinking alcohol.

Contraindications

Hypersensitivity to Mirtazapine or any of the excipients: Mirtazapine is contraindicated in individuals who have a history of hypersensitivity to Mirtazapine or any of the excipients.

Monoamine Oxidase Inhibitors: Taking Mirtazapine with a monoamine oxidase (MAO) inhibitor at the same time is not recommended. Mirtazapine should not be taken within 14 days of starting or stopping monoamine oxidase inhibitor treatment (MAOI).

Side Effect

Dizziness, sleepiness, dry mouth, increased hunger, weight gain, and other adverse effects of Mirtazapine are the most prevalent.

Pregnancy & Lactation

Pregnancy Classification: C. If a patient becomes pregnant or intends to become pregnant while taking Mirtazapine, they should tell their doctor. If a patient is nursing a newborn, they should inform their physician.

Precautions & Warnings

Patients, their families, and their caregivers should be encouraged to be alert to the emergence of anxiety, agitation, panic attacks, insomnia, irritability, hostility, aggressiveness, impulsivity, akathisia (psychomotor restlessness), hypomania, mania, other unusual changes in behavior, worsening of depression, and suicidal ideation, especially early during antidepressant treatment and when the dose is adjusted up or down. Patients who are to receive Mirtazapine should be warned about the risk of developing agranulocytosis. Mirtazapine may impair judgment, thinking, and particularly, motor skills, because of its prominent sedative effect. Clinically significant ALT (SGPT) elevations (≥3 times the upper limit of the normal range) may occur.

Therapeutic Class

Atypical anti-depressant drugs

Storage Conditions

Keep below 30°C temperature in a dry place. Protected from light. Do not freeze. Keep out of reach of children.

Pharmaceutical Name

General Pharmaceuticals Ltd.