Abstract: Asthma is an inflammatory disease of the airways in the lungs and bronchial tubes, the lower airway, that impairs breathing, causes wheezing, coughing and excess mucus and phlegm production. Asthma is the source of about one-fourth of all emergency room admissions. Throat lozenges and orally-retained liquids, such as syrups, containing magnesium are used in the invention to rapidly terminate asthma attacks and prevent asthma attacks. Magnesium lozenges and magnesium orally-retained liquids are effective in asthma rescue. Treatment of asthma with orally-retained magnesium, an essential human nutrient, is much safer than treatment by drugs yet they appear as effective as current drugs. An added benefit from magnesium treatment is relaxation. A preferred composition is 100 mg of magnesium from 400 mg magnesium chloride in a 4-gram lozenge. Magnesium lozenges or orally-retained liquids are administered as needed to treat asthma attacks or prevent incipient asthma attacks.