- Description & Properties:

MITAZAPINE (mirtazapine) tablets are an antidepressant for oral administration. Mirtazapine has a tetracyclic chemical structure unrelated to selective serotonin reuptake inhibitors, tricyclics or monoamine oxidase inhibitors (MAOI). Mirtazapine belongs to the piperazino-azepine group of compounds. MITAZAPINE is supplied for oral administration as film-coated tablets containing 15, 30, or 45mg of mirtazapine in each film-coated tablet.

The mechanism of action of MITAZAPINE (mirtazapine) tablets, as with other antidepressants, is unknown. Evidence gathered in preclinical studies suggests that mirtazapine enhances central noradrenergic and serotonergic activity. Mirtazapine is a potent antagonist of 5-HT₂ and 5-HT₃ receptors. Mirtazapine is a potent antagonist of histamine (H₁) receptors, a property that may explain its prominent sedative effects. Mirtazapine is a moderate peripheral a₁ adrenergic antagonist, a property that may explain the occasional orthostatic hypotension reported in association with its use. 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.

MITAZAPINE (mirtazapine) tablets are rapidly and completely absorbed following oral administration. Peak plasma concentrations are reached within about 2 hours following an oral dose. Mirtazapine is extensively metabolized after oral administration. Mirtazapine has an absolute bioavailability of about 50%. It is eliminated predominantly via urine (75%) with (15%) in feces. The mean elimination half-life of mirtazapine after oral administration ranges from approximately 20 – 40 hours across age and gender subgroups, with females of all ages exhibiting significantly longer elimination half-lives than males (mean half-life of 37 hours for females vs. 26 hours for males). Steady state plasma levels of mirtazapine are attained within 5 days, with about 50% accumulation.

 

MITAZAPINE (mirtazapine) tablets are indicated for the treatment of depression.

MITAZAPINE (mirtazapine) tablets are contraindicated in patients with a known hypersensitivity to mirtazapine.

The most common adverse reaction associated with MITAZAPINE (mirtazapine) tablets include somnolence, nausea, dizziness, increased appetite, weight gain, dry mouth, and constipation.

If a patient develops a sore throat, fever, stomatitis or other signs of infection, along with a low WBC count, treatment with MITAZAPINE should be discontinued and the patient should closely monitored, as this drug may cause Agranulocytosis. It is recommended that MITAZAPINE not be used in combination with an MAOI, or within 14 days of initiating or discontinuing therapy with an MAOI. Because of MITAZAPINE’S potentially significant effects on impairment of performance, patients should be cautioned about engaging in activities requiring alertness. MITAZAPINE should be used with caution in patients with impaired hepatic function and renal impairment. Care should be exercised when mirtazapine is used in patients with a history of mania/hypomania and patients with a history of seizures.

MITAZAPINE should be used with caution in patients with known cardiovascular or cerebrovascular disease that could be exacerbated by hypotension (history of myocardial infarction, angina, or ischemic stroke) and conditions that would predispose patients to hypotension (dehydration, hypovolemia, and treatment with antihypertensive medication). This drug should be used during pregnancy only if clearly needed. Caution should be exercised when MITAZAPINE (mirtazapine) tablets are administered to nursing women. Caution is also indicated in administering MITAZAPINE (mirtazapine) to elderly patients.

Concomitant administration of alcohol, and diazepam or other similar drugs may increase the impairment of cognitive and motor skills produced by MITAZAPINE. Accordingly, patients should be advised to avoid alcohol, and diazepam or other similar drugs while taking MITAZAPINE.

 

Clinically significant ALT (SGPT) elevations may be observed during treatment with MITAZAPINE (mirtazapine) tablets. However, most of these patients with ALT increases did not develop signs or symptoms associated with compromised liver function. While enzyme levels returned to normal despite continued MITAZAPINE treatment.

The recommended starting dose for MITAZAPINE (mirtazapine) tablets is 15mg/day, administered in a single dose (one tablet 15mg daily), preferable in the evening prior to sleep. The effective dose range is generally 15 – 45mg/day. Patients who are not responding to the initial 15mg dose may benefit from dose increases up to a maximum of 45mg / day. MITAZAPINE has an elimination half-life of approximately 20 – 40 hours; therefore, dose changes should not be made at intervals of less than one to two weeks in order to allow sufficient time for evaluation of the therapeutic response to a given dose.

The clearance of mirtazapine is reduced in elderly patients and in patients with moderate to severe renal or hepatic impairment. Consequently, the prescriber should be aware that plasma mirtazapine levels may be increased in these patient groups, compared to levels observed in younger adults without renal or hepatic impairment.

There is no any evidence available from controlled trails to indicate how long the depressed patient should be treated with MITAZAPINE (mirtazapine) tablets. It is generally agreed, however, that pharmacological treatment for acute episodes of depression should continue for up to six months or longer.

At least 14 days should elapse between discontinuation of an MAOI and initiation of therapy with MITAZAPINE( mirtazapine) tablets. In addition, at least 14 days should be allowed after stopping MITAZAPINE before starting an MAOI.

 

Signs and symptoms reported in association with overdose include disorientation, drowsiness, impaired memory, and tachycardia. Treatment should consist of those general measures employed in the management of overdose with any antidepressant. There are no specific antidotes for (mirtazapine) tablets. If the patient is unconscious, establish and maintain an airway to ensure adequate oxygenation and ventilation. Gastric evacuation either by the induction of emesis or lavage or both should be considered. Activated charcoal should also be considered in treatment of overdose.

 

MITAZAPINE – 15mg:Box contains 30 film-coated tablets in blister.

MITAZAPINE – 30mg:Box contains 30 film-coated tablets in blister.

MITAZAPINE – 45mg:Box contains 30 film-coated tablets in blister.