Ephedrine is used to relieve congestion due to colds, flu, hay fever, and allergies, and for temporary relief of shortness of breath, chest tightness, and wheezing due to bronchial asthma. Ephedrine may also be used for other conditions as determined by your doctor. Ephedrine is a decongestant and bronchodilator. It works by reducing swelling and constricting blood vessels in the nasal passages and widening the airway, allowing you to breathe more easily.