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How to Calculate Medication Dosage

What is Medication Dosage?

Weight-based dosing calculates medication amounts proportional to a patient's body weight to achieve therapeutic plasma concentrations. Essential for paediatrics, oncology, and narrow therapeutic index drugs.

Step-by-Step Guide

  1. 1Total dose = weight (kg) × dose per kg (mg/kg)
  2. 2Volume = total dose / concentration
  3. 3Always confirm with British National Formulary (BNF) or pharmacist
  4. 4Round to practical syringe volumes

Worked Examples

Input
Child 25kg · amoxicillin 25mg/kg · suspension 250mg/5mL
Result
Dose = 625mg · Volume = 12.5mL
25×25=625mg; 625÷50=12.5mL (250mg/5mL=50mg/mL)

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