You have pemetrexed and cisplatin in the chemotherapy day unit or during a short stay in hospital. A chemotherapy nurse will give it to you. During treatment, you will usually see a cancer doctor, a chemotherapy nurse or a specialist nurse.ow treatment is given Back to top. You'll be given folic acid and vitamin B12 to take before your treatment with pemetrexed begins and throughout your chemotherapy. It's very important to take folic acid and B12, as they reduce the side effects of pemetrexed.