Overview of Drug Treatment in Children
Drug treatment in children differs from that in adults, most obviously because it is usually based on weight or surface area. Doses (and dosing intervals) differ because of age-related variations in drug absorption, distribution, metabolism, and elimination. A child cannot safely receive an adult drug dose, nor can it be assumed that a child’s dose is proportional to an adult’s dose (ie, that a 7-kg child requires 1/10 the dose of a 70-kg adult). Most drugs have not been adequately studied in children, although federal legislation (the Best Pharmaceuticals for Children Act of 2001 and the Pediatric Research Equity Act of 2003 [both renewed in 2012]) provides the statutory and regulatory authority to begin those studies.
Children are generally subject to the same adverse effects as adults (see Adverse Drug Reactions), but they have increased risk with certain drugs because of differences in pharmacokinetics or because of drug effects on growth and development. Common drugs with unique or higher risk of adverse effects in children are listed in Drugs Manifesting Unusual Toxicity in Children.
Drugs Manifesting Unusual Toxicity in Children
Younger children are at especially high risk of accidental poisoning when they discover and take caregivers’ vitamins or drugs. Infants are at risk of toxicity from drugs used by adults; toxicity can occur prenatally when they are exposed via placental transfer or postnatally when exposed through breast milk (numerous agents—see Breastfeeding : Drugs and Breastfeeding and see Table: Some Drugs Contraindicated for Breastfeeding Mothers) or skin contact with caregivers who have recently applied certain topical drugs (eg, scopolamine for motion sickness, malathion for lice, diphenhydramine for poison ivy).
Adverse effects, including death, have occurred in children receiving OTC cough and cold preparations containing some combination of an antihistamine, sympathomimetic decongestant, and the antitussive dextromethorphan. Current recommendations are that such products should not be given to children < 4 yr.