Carmustine, which is also sold under Gliadel, is used for chemotherapy to treat “several types of brain cancer including glioma, glioblastoma multiforme, medulloblastoma and astrocytoma” (Wikipedia.com) This treatment basically works by hindering the growth of cancer cells. As for the implants, they come in the form of biodegradable discs infused with Carmustine. Plus, they are typically implanted under the skull, allowing for “controlled release of Carmustine in the extracellular fluid of the brain”. The carmustine in the discs works by “sticking to one of the cancer cell's DNA strands” – A process that prevents cell division, thereby killing cancer cells. According to drugs.com, Carmustine implants can cause the following side effects: vision changes, pain when passing urine, depression, chest pain, and signs of meningitis like headache with fever, stiff neck, upset stomach, or confusion. It is worth noting that this treatment may harm an unborn baby, which is why it is necessary that you use birth control in case you are not pregnant. Breastfeeding is also not recommended while using Carmustine implants.