Buspirone inhibits contact hypersensitivity in the mouse

We have observed that 8-4-[4-2-pyrimidyl)-1-piperazinyl]butyl]-8-azaspiro [4.5]decane-7.9-dione, an agent commonly known as buspirone HCl, possesses immunosuppressive activity when administered either topically or systemically, as assessed in a mouse model of contact hypersensitivity. Topical or systemic administration of buspirone significantly reduced the tissue swelling and leukocyte infiltration associated with the elicitation phase of contact hypersensitivity. Buspirone is a safe, widely used drug which has a history of use in humans throughout the world. These data demonstrate a previously unknown pharmacologic activity of buspirone.