I have had a headache for 2 weeks. The MRI test did not show any positive results. Aspirin helps relieve the pain. The doctor wrote me a prescription for Imitrex and promethazine in case I experience nausea. Is the Imitrex supposed to actually get rid of my migraines or is just temporary relief like Aspirin? If that is the case, I am just going to take Aspirin