Table 1.

Examples of drugs commonly used in paediatric medicine for which the paediatric dose is not linearly correlated with body weight

Drug	Therapeutic indication	Adult dose	Paediatric dose
Chloramphenicol	Bacterial infection	50 mg kg−1 day−1	50 mg kg−1 day−1
			neonates: 25 mg kg−1 day−1
Carbamazepine	Epilepsy	5–8 mg kg−1 every 12 h	>12 years: 5–8 mg kg−1 every 12 h
			Children: 3–10 mg kg−1 every 8 h
			Infants: 3–10 mg kg−1 every 8 h
Phenytoin	Epilepsy	2 mg kg−1 every 12 h	Children: 2.3–2.6 mg−1 kg every 8 h
			Infants: 2.3 mg kg−1 every 8 h
			Neonates: 2.5–4.0 mg kg−1 every 12 h
Propofol	Anaesthesia	<55 years: 6–12 mg kg−1 h−1	2 months–16 years: 7.5–18 mg kg−1 h−1
		>55 years: 3–6 mg kg−1 h−1
Busulfan	Cancer	0.8 mg kg−1 every 6 h	≤12 kg: 1.1 mg kg−1 every 6 h
			>12 kg: 0.8 mg kg−1 every 6 h
Tobramycin	Bacterial infection	3 mg kg−1 day−1	Children: 6–7.5 mg kg−1 day−1
			<2 weeks: 4 mg kg−1 day−1
			With cystic fibrosis: 10 mg kg−1 day−1
Enfuvirtide	HIV	180 mg day−1	11–15.5 kg: 54 mg day−1
			15.6–20 kg: 72 mg day−1
			20.1–24.5 kg: 90 mg day−1
			24.6–29 kg: 108 mg day−1
			29.1–33.5 kg: 126 mg day−1
			33.6–38 kg: 144 mg day−1
			38.1–42.5 kg: 162 mg day−1
Oseltamivir	Influenza	150 mg day−1	<15 kg: 60 mg day−1
			15–23 kg: 90 mg day−1
			23–40 kg: 120 mg day−1
Nelfinavir	HIV	2.5 g day−1	7.5–8.5 kg: 0.8 g day−1
			8.5–10.5 kg: 1 g day−1
			10.5–12 kg: 1.2 g day−1
			12–14 kg: 1.4 g day−1
			14–16 kg: 1.6 g day−1
			16–18 kg: 1.8 g day−1
			18–22 kg: 2.1 g day−1
Digoxin	Heart failure	1.4–4.0 µg kg−1 day−1	Children: 3–8 µg kg−1 day−1
			Infants: 7.5–12 µg kg−1 day−1
			Neonates: 4–8 µg kg−1 day−1

References for each drug are provided in the text together with further details about the clinical implication of nonlinearity between drug exposure and descriptors of body size.