Marax is a combination of ephedrine sulfate, theophylline, and hydroxyzine HCl. It widens the airways in the lungs to ease breathing and is used to treat respiratory symptoms associated with the common cold, allergies, hay fever, sinusitis and other respiratory illnesses. Ephedrine is chemically similar to amphetamines and is used as a stimulant, appetite suppressant, decongestant, concentration aid, and hypotension treatment associated with regional anaesthesia. As a bronchodilator, it relaxes the muscles and relieves congestion from bronchial asthma. Ephedrine, exported from China, is derived from a Chinese herb, Ephedra sinica (ma huang). It is marketed in the hydrochloride and sulfate forms. Theophylline is used to relieve and prevent bronchospasm, or narrowing of the airways, in patients who have asthma. It is also prescribed for prevention of emphysema, chronic bronchitis, and other lung diseases, controling wheezing, shortness of breath, and difficulty breathing. It is a safe and effective drug to use in asthma prevention. Hydroxyzine HCl acts as a modifier to the stimulatory action of ephedrine by preventing excitation in patients on Marax.