Paracetamol, the common drug for pain and fever, can cause asthma.

An interim finding — on the eve of World Asthma Day (Tuesday) — of an ongoing clinical study at the Chest Research Foundation (CRF), Pune, has found a link between paracetamol and asthma.

The study will be presented to the international scientific community at the European Respiratory Society Congress in Barcelona in September this year.

Dr Bill Brashier, Senior Research Scientist at CRF, who is conducting the study along with Dr Rahul Kodgule said, “Using a special test called impulse oscillometry we found that when paracetamol is administered on patients with mild asthma, there was a definite increase in airway resistance, suggesting a narrowing of the airways.” According to the scientist, this could be due to the depletive effect of paracetamol on the protective antioxidant lining of the airways.

While the findings are in line with other international studies that have established an association between paracetamol and worsening of asthma, CRF scientists said this is the first time that a causative link is been established.

What this suggests is that one should be cautious while giving paracetamol to those already diagnosed with asthma, especially children, Brashier added.

The widely prescribed drug for fever and pain had come under the scanner when a global study showed that its use in the first year of life was associated with the risk of asthma and excema five to six years later. The Pune-based researchers at CRF were part of the team of scientists from 31 countries who studied two lakh children and the findings were published in The Lancet in September 2008. While paracetamol remains the preferred drug to relieve pain and fever in children, the findings support WHO guidelines recommending that the drug be not used routinely but reserved for children with high fever.