Relpax^® (eletriptan hydrobromide) is a prescription medication that is approved to treat migraine headaches once they start. The medication works to restore the blood vessels in the head to their normal state after they expand during a migraine. Before taking Relpax, be sure to tell your healthcare provider about any medical conditions you may have, such as heart or liver problems, a history of strokes, or high blood pressure. Relpax comes in a tablet form that should be taken by mouth at the onset of migraine symptoms.