- Prescribing Advice for GPs - https://www.prescriber.org.uk -

Antibiotics in pregnancy and paracemamol linked to asthma

The Lancet has published two studies this week that have linked the use of certain antibiotics during pregnancy to an increased risk of cerebral palsy and regular use of paracetamol under the age on 1 year with an increased risk of developing asthma. Both of these studies have been reported in the general media (BBC - Antibiotics and Paracetamol).

The first study is a seven-year follow up of the ORACLE study. ORACLE I compared the use of erythromycin and/or co-amoxiclav with that of placebo for women with preterm rupture of the membranes without overt signs of clinical infection. ORACLE II compared the use of erythromycin and/or co-amoxiclav with that of placebo for women in spontaneous preterm labour and intact membranes.

These studies have provided valuable information to ensure that co-amoxiclav is avoided during pregnancy and that erythromycin is only used in early labour when membranes have ruptured. This recent analysis has shown that both of the study antibiotics are linked to an increased risk of cerebral palsy.

Patients may be concerned about using antibiotics during pregnancy in light of this study however these studies specifically looked at early labour without signs of infection. Patients who are taking antibiotics during pregnancy with signs of infection should be advised of the risks of taking antibiotics compared to the risks of an untreated infection.

The second study used data from the International Study of Asthma and Allergies in Childhood (ISAAC) to investigate the association between paracetamol consumption and asthma.

This study included data from over 200,000 children in 31 countries. It found that use of paracetamol for fever in the first year of life was associated with an increased risk of asthma symptoms when aged 6–7 years (Odds Ratio 1.46 [95% CI 1·36–1·56]). This relationship was dose dependent with an OR of 1.61 for "medium use" and 3.23 for "high use".

The authors are keen to stress that these findings "do not constitute a reason to stop using paracetamol in childhood" but that paracetamol should be reserved for children with a high fever (38.5C or above).

Action: Clinicians should be aware of these studies. Patients and parents are likely to be alarmed by these findings and may seek reassurance.