Paracetamol & Asthma link disputed with new research
Previous research into paracetamol and its link to asthma highlighted a potential risk between the two in early childhood. However this previous research has now been questioned and a different conclusion has been made.
A research team in Australia investigated previous studies that associated paracetamol use and the risk of asthma in childhood. The team analysed 11 studies which had 45 years of data. The issue with the studies in primary analysis is that they found these studies had very varying conclusions and there was only one instance in which respiratory infections were accounted for during pregnancy. This meant that the evidence showed did not involve other factors such as previous health issues.
In six of the studies, exposure to paracetamol was analysed before the children were two years old. This was due to the stage of development of children’s lungs being critical during this period. The studies evaluated that paracetamol increased the risk of asthma in later life however when respiratory infections were accounted for, the authors described the association as “considerably weakened”. The team was also unable to draw sufficient conclusions about the role played by maternal respiratory infections due to only one study taking this into account.
The team concluded with the following –
“The evidence of an association between early life paracetamol and asthma is often overstated, and there is currently insufficient evidence to support changing guidelines in the use of this medicine”.
The team noted that a trial looking into the link is unlikely as it would involve a placebo-controlled trial on babies which many parents would refuse.
Prof Seif Shaeen, Clinical Professor of Respiratory Epidemiology at Barts and the London School of Medicine and Dentistry, Queen Mary University of London, was one of the teams who first reported the link between paracetamol and asthma 14 years ago. He commented with the following –
“Whilst the jury is out regarding whether the link between infant paracetamol use and childhood asthma is confounded by respiratory infection, there is no evidence to suggest that respiratory infections in pregnancy confound the association between prenatal exposure and asthma.
Given that primary prevention trials may never happen, I would argue that there is nothing to be lost by advising pregnant women and parents of young children to minimise the use of paracetamol.
Paracetamol is probably overused and it would seem prudent to discourage unnecessary or inappropriate use at the present time”.
Dr Samantha Walker, director of research and policy at Asthma UK, said-
“We welcome the findings of this report which concludes that an association between early life exposure to paracetamol and asthma has probably been overstated. According to the study authors, the current evidence for a link between the drug’s use and the development of asthma is ‘weak’ and so parents should not worry about taking paracetamol during pregnancy or giving it to young children.
Research like this is welcome because despite asthma affecting 1 in every 11 children, years of research underfunding means it remains a relative mystery. These findings provide reassurance to parents of young children that paracetamol is a safe and effective treatment for pain and fever if taken according to the manufacturer’s directions.”
The study is published online in the Archives of Disease in Childhood.
 “Link between kids’ asthma and paracetamol ‘weak’”, Peter Russell, WebMD UK Health News, http://www.webmd.boots.com/asthma/news/20141126/kids-asthma-paracetamol-link-weak
 “Asthma unlikely to be linked to paracetamol”, Louise Prime, OnMedica, http://www.onmedica.com/newsarticle.aspx?id=78e9833f-cc97-43fe-99c3-a9a72dd92569
 “Paracetamol link to asthma risk ‘has been overstated’: Experts say evidence is not strong enough to warrant warnings”, Jenny Hope, Mail Online, http://www.dailymail.co.uk/health/article-2849727/Experts-say-paracetamol-link-asthma-risk-overstated.html