A new approach to asthma treatment

According to latest research drug size is the key to asthma treatment. Asthma inhalers could be made more effective if they used bigger drug particles. Researchers believe the finding could lead to less wasteful and more effective treatments for nearly 150 million people affected worldwide by this disease. Current asthma inhalers are known to be only 20% efficient. They contain a range of particle sizes, but many do not end up where they are most needed. The key to successful treatment is to target accurately the areas in the airways which are narrowed and inflammed. The researchers from the National Heart and Lung Institute, Imperial College London, tested 12 asthmatic patients' response to three different particle sizes of the drug salbutamol, which is used to increase the width of the airways. They have found that accuracy can be increased by altering the size of the drug particles used in reliever treatments. They were able to map where the particles were going by attaching a radioactive tracer. They found that although small particles were more likely to reach the lungs, they often ended up in sites where they have little effect. In contrast, larger sized particles ended up in the areas where they were most likely to be of use. The researchers also found that if only larger particles were used, the dose could be reduced to just one tenth of that delivered by conventional inhalers with the same effect. This was because fewer particles failed to reach their intended target. This could lead to the development of lower dose inhalers, which would save money and reduce the risk of side effects. This could be particularly important with inhaled steroids if future studies show similar results in steroid particle size. This is an important finding since there has been little change in asthma medication and the way it is delivered over the last few decades. The next step would be to analyse the most effective drug particle sizes for different respiratory diseases and for the different inhaled drugs used in these conditions. It is vital to conduct further work be to see whether children, who have smaller lungs and developing airways, respond in the same way as adults to larger drug particles.