Synopsis
Calculate, prescribe, dispense and administer paediatric medicines safely using current weight, age, indication, formulation, organ function, dose ceilings and independent verification.
- Use the current measured weight in kilograms and record date, time and context; kilograms belong visibly on both the observation and prescribing record.
- First-line UK dose reference is the current BNFC monograph for the exact indication, route, age and formulation, supplemented only by clearly governed specialist guidance.
- Write the formula before calculating: dose per administration equals prescribed mg/kg/dose multiplied by weight in kg.
Key red flags
A calculated dose above the BNFC age or adult maximum, or outside the local electronic hard limit, must be resolved before administration rather than accepted because the arithmetic is correct.
Investigation priorities
Provide the denominator for dose and fluid calculations.
Identify the authoritative age, route, indication, interval and maximum.
Management branches
A medicine is prescribed in mg/kg or micrograms/kg.
- Verify patient, current kg weight, indication, route, age band and the current BNFC dose expression.
- Calculate the dose with written units, divide daily doses correctly and apply single and daily maxima.
Key medicines
Intramuscular adrenaline for anaphylaxisFor children, give 10 micrograms/kg intramuscularly using 1 mg/mL adrenaline into the anterolateral thigh, with a maximum single dose of 500 micrograms; repeat after 5 minutes if airway, breathing or circulation compromise persists.
Intravenous paracetamol calculation exampleFor a child above 10 kg without specific risk factors, a common product regimen is 15 mg/kg intravenously per dose every 4 to 6 hours, no more than 4 doses and 60 mg/kg in 24 hours, capped at 3 g daily below 50 kg; verify the current BNFC and product age and weight band before prescribing.