By Rich McManus
Photos by Ernie Branson
Dr. Jeffrey Drazen, editor-in-chief of the New England Journal of Medicine and Parker B. Francis professor of medicine, emeritus, at Harvard Medical School, demonstrated his mastery of study design as he described several decades worth of clinical trials focusing on asthma, a respiratory ailment that has been on the rise in this country and whose root causes remain unknown.
"We still don't understand the primary pathobiology of asthma — we could treat it if we did," he told a large audience in the newly refurbished Lipsett Amphitheater, where he spoke on Feb. 12 as the sixth of 10 lecturers in the 2002-2003 Contemporary Clinical Medicine: Great Teachers series, a special feature of Clinical Center Grand Rounds.
 | Dr. Jeffrey Drazen lectures on new treatments for asthma at a Great Teachers presentation of Clinical Center Grand Rounds. |
Drazen said physicians currently treat asthma based on how severe it is. The spectrum of severity includes four categories:
- Mild Intermittent — About half of all asthma patients fall into this category, which is characterized by fewer than 2 or 3 asthmatic episodes per week, and no difficulty sleeping at night. No continuous control treatment is necessary.
- Mild Persistent — Patients typically have tightness and wheezing weekly, but relatively normal lung function overall. One controller is sufficient to manage the illness.
- Moderate Persistent — Daily episodes characterize this stage, but the flare-ups are manageable with two medications.
- Severe Persistent — Episodes occur daily, despite therapy with more than two controllers.
Drazen said that therapies addressing the symptoms of asthma are "effective, but not terribly so. They prevent exacerbations, but they don't really modify or address the underlying problem." There are a number of downsides to long-term use of inhaled corticosteroids (ICS), he reported. Some studies have shown mild detrimental effect on bones, including a small effect on height. "Bone loss can be accelerated through use of steroids, but the effect may be small and hard to detect," he said. "Over time, higher ICS use leads to bone loss. It's not a huge risk, but it does enhance (loss)." Drazen said steroids must be used with caution; there are systemic effects, including some suppression of the hypothalamic-pituitary axis.
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| Drazen chats before his Feb. 12 lecture with Dr. Elizabeth Nabel, director of NHLBI's Clinical Research Program, and Dr. Dean Metcalfe, chief of the mast cell biology section in NIAID's Laboratory of Allergic Diseases. |
Interestingly, asthma is more common in boys than girls, he reported, but a switch occurs in adulthood, when the disease becomes more common in women than men.
Drazen said doctors who manage persistent asthma should choose an inhaled steroid that has the maximum pulmonary effect and the minimum downside. "Do the least you can do," he advised, recommending low-potency ICS therapy.
Comparing oral anti-leukotriene therapy, which arrived in 1997, to ICS, Drazen said studies give ICS a slight edge in improving symptoms, although many patients find it easier to take a pill than take puffs off of an inhaler. "Neither treatment is great," he cautioned. "We need to do better."
Some asthma patients, he reported, have been reluctant to get influenza vaccines, for fear of exacerbating their asthma. He demonstrated that such concerns are groundless.
Drazen concluded with recommendations for the four categories of severity: for mild intermittent asthma, 8 rescue inhalers per year are probably sufficient; for mild persistent sufferers, anti-leukotriene therapy or low-potency ICS should do the trick; for moderate persistent patients, long-acting beta agonist therapy and ICS is the ticket; and for severe cases he advised, "Get help!"
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