Radical asthma therapy upheld
A new study conducted at the College of Pharmacy calls into question a widely-used medical treatment for asthma and coincides with the Food and Drug Administration’s critical review of existing asthma treatments.
Richard A. Bond, professor of pharmacology at the College of Pharmacy, has recently published work suggesting that using a class of drugs known as beta-blockers would be more effective in treating chronic asthma than the standard treatment of using drugs known as beta-agonists.
In his newest findings, published in this month’s Proceedings of the National Academy of Sciences, Bond’s lab looked at mice lacking the beta-2 receptor. These mice could not be induced to develop asthma, a finding that suggests stimulation of the beta-2 receptor plays a role in causing asthma.
‘Whether we block the receptor chemically (with beta-blockers) or the receptor just isn’t there, the results are the same,’ Dr. Bond said.
Asthma is a chronic respiratory disease that is characterized by constriction and inflammation of the airways in the lungs and causes difficulties in breathing, ranging from moderate to severe. One biological molecule that regulates the constriction of the airways is the beta-2 receptor. When activated, the receptor causes airways to dilate, making breathing easier.
For over 40 years, the standard treatment for asthma has been to use beta-agonist drugs that activate these receptors. They immediately make breathing easier, but Bond said his research calls their long-term effectiveness into question.’ He found that by blocking these receptors instead of activating them, airways relaxed, and the results appeared to be beneficial in chronic asthma.
His earlier work with mice suggested beta-blockers are better suited for long-term management of asthma. When beta-blockers were given over a 28-day period, the mice showed less constriction of the airways, indicating a reduction of asthma symptoms.
‘The older drugs worked in the sense that people immediately felt better, but in the long term they had more complications,’ Dr. Bond said. ‘Beta-agonists are wonderful drugs when used acutely. The problem is that asthma is a chronic disease.’
His view was recently supported in a study released by the FDA in December that showed increased risk of hospitalization and of breathing related deaths in asthma patients treated solely with beta-agonists.
His suggestion that asthma be treated with drugs that do exactly the opposite of current therapies was initially met with skepticism, Bond said.
‘I remember I gave a talk to the European Respiratory Society and I was first met with open laughter. After I showed the data there wasn’t any more laughing,’ Bond said.
Bond hopes his findings will help the medical community establish practices that offer the best treatment for both acute and chronic phases of asthma.’There is a potential for reconciliation between using both beta-agonists and beta-blockers together. Each is suited to address a particular aspect of the disease,’ Bond said.