Independent.co.uk
Paracetamol given to babies is linked to global rise in asthma
By Jeremy Laurance, Health Editor
Friday, 19 September 2008
The global rise in asthma over the past 50 years, which has mystified doctors for decades, may be linked to the growing use of paracetamol, researchers suggest today.
A major international study, involving more than 200,000 children in 31 countries, has found those treated with paracetamol in the first year of life had a 46 per cent increased risk of developing asthma by the age of seven.
The risk was up to three times higher among children who were the heaviest users of the drug, indicating a strong dose-dependent link. The study, published in The Lancet, adds to a growing body of evidence linking the painkiller with the disabling lung condition. Eczema and rhinitis were also increased. Previous research has linked asthma with exposure to paracetamol in the womb, infancy, childhood and adulthood.
A study by the Global Allergy and Asthma Network of 1,000 people, half of whom had asthma, found the incidence of the condition was increased threefold in people who used the drug weekly. The results are published in the European Respiratory Journal.
Paracetamol came into widespread use in the 1950s and sales have grown rapidly since. In the UK, 580 million tablets were sold in 2001-02. Paracetamol replaced aspirin as the painkiller of choice in children because of concerns about Reye's syndrome, a potentially fatal condition linked with aspirin.
The growth of the asthma epidemic started in the 1950s and the numbers affected in the UK approximately doubled every 14 years until the 1990s. There are around five million people with the condition in the UK. In 2005, more than 70,000 people were admitted to hospital with asthma attacks and 1,318 died.
The leading theory to explain the rise has been the hygiene hypothesis ? that as we lead cleaner, germ-free lives and are exposed to fewer illnesses in childhood, our immune systems are underdeveloped and over-react when exposed to allergens such as house dust mites and cat hair. But this does not account for the increase in asthma in places remote from the developed world.
Paracetamol sales, by contrast, have grown worldwide in both developed and developing countries. Some researchers claim a link between local paracetamol sales and the incidence of asthma. The drug is thought to suppress production of the antioxidant glutathione in the lungs, leading to inflammation when exposed to allergens.
The authors of The Lancet study, Professor Richard Beasley of the Medical Research Institute of New Zealand and colleagues, stress that they have established an association not a cause.
"Paracetamol remains the preferred drug to relieve pain and fever in children... [However] it should not be used routinely but should be reserved for children with a high fever (38.5C or above)," they say.
Critics say the infections for which the paracetamol was given may have triggered the asthma rather than the drug itself. Professor Glenis Scadding, a consultant allergist at the Royal National Throat, Nose and Ear Hospital, London, said: "It may be that the actual cause is recurrent viral colds."
Specialists say research to confirm the findings is urgently needed.
Advice for parents
* Paracetamol and other drugs should not be used routinely in children but reserved for when they are ill.
* In most cases a child with a mild fever will get better. Doctors say they often prescribe drugs to reassure the mother rather than treat the infant.
* Tepid sponging to keep the child comfortable and reduce temperature is the first line of treatment.
* If the child is in discomfort, pain or has a fever above 38.5C, treat with paracetamol.
* High fevers in babies and young children can cause febrile convulsions and have serious consequences.
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