Nocturnal asthma and exercise-induced bronchospasm. Why they occur and how they can be managed.

Asthma is increasing in prevalence and morbidity worldwide. Worsening of asthma symptoms during sleep and following exercise is an important component of this morbidity. Better recognition and management of nocturnal asthma and exercise-induced broncho-constriction should lead to improved outcomes. Measures to alleviate nocturnal asthma include elimination of exposure to allergens, use of measures to control contributing factors (rhinitis, sinusitis, gastroesophageal reflux, sleep apnea), maximization of the dosage of daytime asthma medications, and appropriately timed use of medications such as a long-acting inhaled beta 2 agonist, a once-daily sustained-release theophylline product, and an oral corticosteroid. Bronchoconstriction after exercise can be decreased by physical conditioning, warm-up exercises, wearing of a face mask in cold weather, postponement of exercise until at least 2 hours after a meal, and pretreatment with an inhaled beta agonist. Pretreatment with inhaled cromolyn sodium (Intal), nedocromil sodium (Tilade), or ipratropium bromide (Atrovent) may be added if necessary.