It turns out that lung medications may not work properly if the person taken them is exposed to cigarette smoke or the flu virus. Scientists discovered that the effectiveness of symptom-reliever medication for those with chronic obstructive pulmonary disease (COPD) goes down when exposed to outside sources.

COPD is the name for lung diseases, including emphysema, chronic bronchitis and chronic obstructive airways disease. The main cause of COPD is smoking, and the chances of developing COPD increases the longer that an individual has been smoking.

Those that suffer from COPD have difficulty breathing, mainly due to airflow being obstructed. They also suffer from the persistent production of phlegm and frequent chest infections.

"There is a clear need for new therapies that can overcome the limitations of current drugs used to treat COPD and associated flare-ups," said Ross Vlahos of RMIT University in Melbourne, Australia, one of the researchers of the new study. "When combined with knowledge gained through clinical research, animal models utilizing cigarette smoke exposure are a valuable tool in the quest to identify new therapies for this life-changing condition."

One of the most common drugs used to relieve the symptoms of COPD is salbutamol. This drug works by dilating a patient's airways, which makes it easier for them to breathe. However, the effectiveness of drugs such as this one can be limited.

In this latest study, the researchers assessed sections of lungs exposed to cigarette smoke and a version of the influenza A virus. They found that lung tissue exposed to smoke and viral infection was less responsive to salbutamol.

"The findings of this study suggest that cigarette smoke and respiratory virus infections may impair the ability of salbutamol to effectively bronchodilate the airways," said Sebastian Johnston, one of the researchers involved in the study. "These findings emphasize yet again that smoking is bad for you, and especially so if you have asthma or COPD. It would be interesting to determine whether the other commonly used reliever bronchodilator ipratropium bromide, which acts via a different mechanism, is similarly impaired by cigarette smoke and/or viral infection."

The findings were published in the April edition of the journal Clinical Science.