Mirtazapine (in pets) is commonly used as which of the following?

• A. Antihistamine
• B. Anti-inflammatory
• C. Antifungal
• D. Appetite stimulant

Answer: (D)

Mirtazapine is used in pets mainly as an appetite stimulant, especially in cats. Its action in the brain helps explain why this works: it blocks central alpha-2 adrenergic receptors, which raises the release of norepinephrine and serotonin in appetite-regulating areas of the hypothalamus. That uptick in signaling can increase hunger and interest in food. At the same time, mirtazapine blocks certain serotonin receptors, including those involved in nausea (like 5-HT3), which can lessen nausea and make eating more appealing. This combination makes it a practical option for animals with reduced appetite due to illness or chemotherapy. It isn’t an antihistamine, anti-inflammatory, or antifungal, because those types of drugs act on entirely different systems and purposes.