Patients who are suffering from low blood pressure because of shock or because they are under anesthesia may be given an phenylephrine injection. This medication may also be injected to prolong anesthesia during surgical procedures or to treat certain types of irregular heartbeats. Men who have painful or prolonged erections sometimes are given this drug as well.
This medication can cause heart problems. If you have chest pain, irregular heartbeat, tingling in the hands and feet or dizziness, you need immediate medical attention. You also need help if you have an allergic reaction to the medication, including swelling of the mouth or tongue, difficulty breathing or breaking out in hives.