Mirtazapine is in a class of medications called antidepressants. It also has been used as an antianxiety medication, antiemetic, and appetite stiumulant. It works by enhancing adrenergic and serotonergic neurotransmitter activity in the brain. Mirtazapine is also an antagonist of 5-HT3 and histamine receptors. Mirtazapine is available as a tablet and  an oral disintegrating tablet. As with other antidepressants, patients may need to take mirtazapine for several weeks to experience the full benefits and it may cause withdrawal symptoms on discontinuation. Mirtazapine has been evaluated for anorexia, chemotherapy-induced nausea and vomiting, depression, sleep-wake disturbances, and hot flashes.