Calcineurin inhibitors (CNIs) suppress the activity of your immune system. They're used to prevent organ rejection after a transplant and to treat various autoimmune conditions, such as lupus and eczema.CNIs come in oral pills, topical products, and eye drops. Examples include tacrolimus (Prograf, Protopic, Astagraf XL), cyclosporine (Neoral, Restasis, Sandimmune), and pimecrolimus (Elidel).