Medicine dosing in childhood obesity

UK Medicines Information service (UKMI) in conjunction with the Neonatal and Paediatric Pharmacist Group (NPPG) have produced updated guidance on how to dose medication in children who are obese.

The updated document provides a review on how to calculate doses in children who are obese and provides a table of dosing recommendations for commonly prescribed medicines. The document also summarises the following: 

  • There is a lack of pharmacokinetic data on the use of commonly used drugs in obese children, therefore knowledge of which size descriptor to use in determining the optimum dose for this group of patients is limited.
  • Drug-dosing guidelines are typically derived from available data in adults who are obese.
  • Height measurements are needed on admission to hospital to identify obesity and to calculate doses based on the appropriate size descriptor.
  • Evidence-based, locally agreed guidance is required indicating which method to use for IBW calculation and which size descriptor to use for commonly used drugs in children to reduce variability and ensure optimal effectiveness and safety.
  • Although this information is provided to guide prescribers on dosing, each patient is individual and they should be clinically monitored and regularly reviewed for side effects (safety) and treatment response (efficacy).
  • In an emergency setting, actual body weight (or estimated body weight) may be used to prevent delay of treatment.

Healthcare professionals involved in prescribing or administering medication to children who are obese are advised to refer to this document for dosing guidance.