Becoming a little short of breath or fatigued when you exercise is normal, particularly if you are out of condition, according to MayoClinic.com. If you have more severe symptoms, you may be experiencing exercise-induced asthma, also called exercise-induced bronchospasm. These symptoms may include feeling out of breath during or after exercising. Although the medication furosemide is generally not intended for treating or preventing asthma, this drug has been shown to help with exercise-induced asthma.
The Problem
As with any form of asthma, exercise-induced asthma symptoms develop when the airways tighten and produce extra mucus, notes MayoClinic.com. For some people, exercise is the only asthma trigger, while for others, exercise is one of a number of triggers. Symptoms may include coughing, wheezing, feeling short of breath, experiencing chest tightness or pain and feeling fatigued during or after physical activity.
Furosemide
Furosemide, commonly known as the brand Lasix, is a prescription diuretic medication mainly used for treating high blood pressure and fluid retention, as noted by eMedTV. It can relieve fluid retention and swelling caused by congestive heart failure, kidney failure and cirrhosis.
Off-Label Use
Doctors are allowed to prescribe legal medications for health conditions even if the U.S. Food and Drug Administration has not approved the drug for that particular condition. Oral furosemide is used off-label to treat and prevent asthma symptoms by inducing airway smooth muscle relaxation, preventing inflammation and increasing airway and lung hormone levels, explains the 2006 book "The Guide to Off-Label Prescription Drugs" by Kevin Loughlin and Joyce Generali. Furosemide is useful for chronic asthma as well as asthma triggered by exercise, cold air and chemical sensitivities. Although research shows it also works as an inhaled substance, furosemide is not available commercially in an inhaled preparation. This preparation is only available to participants in clinical studies.
Potential
A study by C. H. Larramendi and colleagues published in the March-April 1997 issue of "Allergologia et Immunopathologia" mentions previous research finding that inhaled furosemide is useful for preventing exercise-induced asthma. The current study evaluated the FEV1 -- forced expiratory volume in the first second -- in asthmatic patients after exercise. The FEV1 measures the volume of air a person can force out in one second after taking a deep breath, an ability that decreases with asthma. Inhaled furosemide improved the FEV1 an average of 11 percent.
