Asthma
and paracetamol have been looked at before so this is an on-going issue with no firm conclusion:
Paracetamol and asthma
“Regular users of
paracetamol are nearly three times more likely to have asthma”, the Daily
Mail reported today. It said that a study had analysed the frequency of
painkiller use in people with and without asthma in Europe and its findings
suggested that using paracetamol at least once a week increases the risk of
suffering symptoms. Other painkillers apparently did not have the same effect.
The study behind
this report is a case-control study and by virtue of its design, it cannot
prove causation (that paracetamol increases asthma). It also cannot rule out
reverse causation (that asthma causes people to take more painkillers).
However, when considered alongside the findings of other studies, these results
suggest that there may be an association between use of paracetamol and asthma
that needs further exploration. This is not a new concern, and researchers have
been investigating this for some time. As the researchers conclude, “there is
now a need to carry out suitable intervention studies to determine whether the
link is causal”. Prospective studies, preferably those that randomly allocate
healthy participants to having paracetamol or not, would produce more
conclusive results.
For more detailed information please click a link below.

Sources: http://www.nhs.uk/news/2008/09September/Pages/Paracetamolandasthma.aspx
http://news.bbc.co.uk/1/hi/health/7623230.stm