Proposed MHRA changes to UK children's paracetamol dosing recommendations: modelling study

Abstract

Objectives Paracetamol is the most commonly administered medicine to children. A recent study highlighted the risk of overdose of paracetamol using British National Formulary for Children (BNFC) age-based dosing guidelines. This current study assesses the safety of changes to the UK paracetamol product dosing system proposed by the Medicines and Healthcare products Regulatory Authority (MHRA) which include a larger number of narrower age bands and a single dose per age band. Design Theoretical comparison of the proposed MHRA dosing system with the product dosing instructions of a commonly prescribed form of paracetamol in the UK. Setting United Kingdom Participants Proposed MHRA dosing recommendations and current product dosing instructions were compared using a previously validated model. Main outcome measures For both dosing recommendations, single and cumulative daily doses of paracetamol for boys and girls at the 9th, 50th and 91st centiles for weight were calculated for 3 month, 1 year, 6 year and 12 year age groups. Results With the current product dosing instructions, underweight children are at risk of receiving approximately two times the recommended single and cumulative daily dose of paracetamol, particularly at age 1 year and 6 years. This risk is negligible when the same model is applied to the proposed MHRA dosing system, whereby underweight, average weight and overweight children at all ages receive doses marginally above or within the recommended dose range or limit. Conclusion The proposed MHRA dosing recommendations for paracetamol use in children are effective at reducing the risk of paracetamol overdose in children of all ages, when compared with current product dosing instructions.