Mirtazapine: Price, Dosage & Where to Buy

Mirtazapine is an antidepressant used to treat major depressive disorder in adults, and it requires a prescription in the United Kingdom. It is available as oral tablets, film-coated tablets and tablets that dissolve in the mouth; treatment needs monitoring for changes in mood and side effects such as sleepiness, increased appetite and weight gain.

Mirtazapine is indicated for major depressive disorder in adults. This is the condition described in the label as its treatment use; the label does not list separate indications for sleep problems or other conditions.

Although sleepiness can occur during treatment, this is described as a side effect rather than a separate treatment purpose. Safety and effectiveness for major depressive disorder in children have not been established, and the tablets are not approved for use in children.

Mirtazapine is an antidepressant that changes signalling between nerve cells in the brain. It acts on receptors involved in controlling the release and activity of chemical messengers, including noradrenaline and serotonin, which are involved in mood regulation.

Rather than simply increasing every serotonin signal, it blocks certain receptors and alters how these messages are passed along. Its effects on histamine receptors also help explain why sleepiness can occur during treatment.

The label lists oral tablets and film-coated tablets in strengths of 7.5 mg, 15 mg, 30 mg and 45 mg. The label lists orally disintegrating tablets in strengths of 15 mg, 30 mg and 45 mg. The usual starting dose is 15 mg once daily, administered orally, preferably in the evening before sleep.

The label lists a maximum recommended dose of 45 mg once daily if the initial response is inadequate. The label lists dose-change intervals of no less than 1 to 2 weeks to allow assessment of the response. The label lists gradual dose reduction when treatment is discontinued, rather than abrupt stopping whenever possible.

The label lists possible dosage decreases for moderate to severe kidney impairment or liver impairment, and dosage adjustments with certain interacting medicines. Before treatment begins, the label calls for screening for a personal or family history of bipolar disorder, mania or hypomania.

A missed dose should not be made up by doubling the next dose. A pharmacist can advise how to resume the prescribed schedule, particularly if more than a single dose has been missed. Repeated missed doses or abrupt stopping may lead to discontinuation symptoms, so changes to treatment should be discussed with the prescriber.

Published observational studies and reports have not reliably identified a mirtazapine-associated risk of major birth defects, miscarriage or adverse maternal or fetal outcomes. Untreated depression also carries risks during pregnancy, and stopping antidepressants can increase the likelihood of depression returning. Mirtazapine is present in breast milk at low levels; most reported cases have not described adverse effects in breastfed infants.

Effects on milk production are unknown. Treatment decisions should consider the mother's clinical need and potential effects on the infant.

The label specifies storage at 20° to 25°C, protected from light and moisture. Keep the tablets in a tight, light-resistant container with a child-resistant closure to maintain quality and keep them out of children's reach.