Clindamycin + Isotretinoin is a combination of two medicines: Clindamycin and Isotretinoin which treat pimples (acne). Clindamycin is an antibiotic which works by penetrating into the skin and killing acne-causing bacteria. Isotretinoin is a form of vitamin A. It works by reducing oil production in the skin, replenishes acne-prone skin and helps keep your pores open.