Vasograin Tablet is a combination of four medicines: Caffeine, Ergotamine, Paracetamol and Prochlorperazine, which treats migraine. Ergotamine is an ergot alkaloid which works by preventing blood vessels in the head from expanding and causing headaches. Caffeine increases the absorption of ergotamine and further narrows the widened blood vessels. Paracetamol is an analgesic (pain reliever). It blocks the release of certain chemical messengers in the brain that are responsible for pain. Prochlorperazine is an antiemetic (anti-nausea medicine) which works by blocking signals in the part of your brain that causes nausea/vomiting.