Asthma Hits Hardest At Night, So Should Medication

Expert says traditional treatment ignores timing of severe symptoms.

The symptoms suffered by some 10 million Americans with asthma can be as different as night and day, with the time of day often a key factor in their severity, according to an expert who contends the patterns of the disease should be considered when treating it.

"The night belongs to asthma," says Richard Martin, M.D., Head, Division of Pulmonary Medicine, National Jewish Center for Immunology and Respiratory Medicine, Denver, and Professor of Medicine, University of Colorado Health Sciences Center, USA. "Morbidity and mortality is greatest during sleep-related hours...if you control the nighttime asthma, you can change the severity of asthma."

Since the greatest prevalence of asthmatic symptoms occurs around 4 a.m., Dr. Martin reasons medication therapies should be timed to take effect when inflammation in the airways is the greatest. However, he adds, "most physicians are taught that it doesn't matter if it's asthma or heart disease -- divide medications equally throughout the day."

Dr. Martin spoke at an American Medical Association media briefing on chronotherapeutics -- the synchronizing of drug therapies with the rhythms of the human body

The approach could also help offset the sneezing, nasal congestion and runny nose and eyes that come with allergies. For instance, Martin says hay fever symptoms peak in the morning. He adds that some studies show taking an antihistamine in the evening, rather than during the day, helps block symptoms before a patient gets out of bed, rather than waiting for symptoms to begin.

The chronobiological changes involved can also effect the outcome of skin tests used to diagnose allergies as well as efforts to gauge the severity of symptoms. "An asthmatic patient exposed to an allergen he or she is sensitive to usually feels an immediate tightness in the airways, with about 40 percent suffering a secondary and more severe response hours later," Dr. Martin says. "However, this secondary response depends on the time of day or night the allergen is inhaled. It occurs almost 100 percent following an evening exposure."

While researchers have spent the last decade studying how to change therapies in response to chronobiological rhythms, "it is a slow process from understanding research to changes in the clinical practice." But Dr. Martin says the issue may become even more important in treating asthma, which is showing an increasing prevalence in the United States and other developed countries. (Source: American Medical Association, Physicians dedicated to the health of America, 515 North State Street, Chicago, Illinois 60610, Telephone: 312-464-4443, FAX: 312-464-5839)

Editor's note: Please check the American Medical Association on the Web at: http://www.ama-assn.org/