Children are not just small adults — their organ function, body composition, and drug metabolism differ significantly. Weight-based dosing ensures the correct dose relative to body size. Underdosing leads to treatment failure; overdosing can cause toxicity. Always verify doses against age-appropriate references.

For most medications, use actual body weight. For obese children (>95th percentile BMI), some drugs should be dosed on ideal body weight or adjusted body weight to avoid toxicity. Always check the specific medication's prescribing guidelines.

Pediatric doses calculated by weight should not exceed the usual adult dose for that medication. Always check the maximum single and daily dose. For example, ibuprofen is dosed at 10 mg/kg per dose, but the max single dose is 400–600 mg regardless of weight.

Always cross-reference with: the medication package insert, a pediatric drug reference (Lexicomp, Harriet Lane Handbook), hospital formulary guidelines, and have a pharmacist review for high-risk medications. Double-check units (mg vs mcg) and decimal places.