Cosmegen (generic: dactinomycin) is a prescription medication that is used in various types of cancer chemotherapy. Cosmegen belongs to a group of antibiotics called actinomycins. It is thought to work by binding to the DNA of cancer cells and inhibiting RNA synthesis, causing the cancer cells to die.  

This medication comes in liquid form and is infused into a vein (IV) by a healthcare provider at a hospital or other medical facility. How often you will receive Cosmegen depends upon the condition being treated.

Common side effects include hair loss, hives, and difficulty breathing. Cosmegen may lower blood cells involved in fight infection; therefore, you should avoid people with known infections.