Drug treatment in children differs from that in adults, most obviously because pediatric drug dosing is usually based on weight or surface area (1). Doses (and dosing intervals) differ because of age-related variations in drug absorption, distribution, metabolism, and elimination (see Pharmacokinetics in Children) (2).Thus, children are not given adult doses. Furthermore, it cannot 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, but, legislation in the US, the Best Pharmaceuticals for Children Act of 2001 and the Pediatric Research Equity Act of 2003 (both made permanent in 2012 [3]) now provide the statutory and regulatory authority to incentivize and require therapeutic trials in children. As a result of these acts, numerous labeling changes were made to provide dosing, pharmacokinetic, and safety information for children (see also the U.S. Food and Drug Administration [FDA] 2020 status report).
General references
1. Le J, Bradley JS: Optimizing antibiotic drug therapy in pediatrics: Current state and future needs. J Clin Pharmacol 58 (supplement 10):S108–S122, 2018. doi: 10.1002/jcph.1128
2. van den Anker J, Reed MD, Allegaert K, Kearns GL: Developmental changes in pharmacokinetics and pharmacodynamics. J Clin Pharmacol 58 (supplement 10):S10–S25, 2018. doi: 10.1002/jcph.1284
3. Bourgeois FT, Kesselheim AS: Promoting pediatric drug research and labeling—Outcomes of legislation. N Engl J Med 381(9):875–881, 2019. doi: 10.1056/NEJMhle1901265
Adverse effects and toxicity
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. Some common drugs with unique or higher risk of adverse effects in children are listed in table Some Drugs Manifesting Differential Toxicity in Children.
Some Drugs Manifesting Differing Toxicity in Children
Drug | Clinical Syndrome | Mechanism | Comments |
|---|---|---|---|
Cyanosis | Formation of methemoglobin (ferrous iron oxidized to ferric iron) | Incidence rare | |
Affects only neonates | |||
Respiratory depression Death | Genetic variant | ||
Diphenoxylate | Respiratory depression Death | CNS depression (in immature CNS) | Overdose syndrome, usually in children < 2 years |
Fluoroquinolones | Cartilage toxicity | Unknown | Suspected based on animal studies, but adverse effects in humans unproved—short-term use may be safe |
Seizures CNS toxicity | Probably enhanced absorption in children | Should not be used in children < 50 kg (alternative should be used) | |
Altered CNS function Extrapyramidal effects Opisthotonus Bulging fontanelles | Actions via multiple CNS receptors | Febrile and dehydrated infants especially at risk | |
Selective serotonin reuptake inhibitors | Suicidal ideation | Unknown | Increased incidence of suicidal ideation in children and adolescents |
Discoloration and pitting of tooth enamel | Chelation with calcium in growing teeth | Not given to children < 8 years | |
* See also the American Academy of Pediatrics' clinical report | |||
CNS = central nervous system. | |||
Younger children are at especially high risk of accidental poisoning when they discover and take caregivers’ vitamins or drugs, even vitamins and drugs that have been thrown away. When discarding a drug, consumers may seek disposal instructions on the package insert or review information at the FDA web site. Options include taking the drug to a local drug collection program (possibly at a pharmacy or local law enforcement site) or mixing the drug with an undesirable material (eg, cat litter, coffee grounds), tightly wrapping it in plastic, placing it in a watertight container or bag, and then disposing it in the trash.
Infants may be at risk of toxicity from drugs used by adults; toxicity may occur prenatally when they are exposed via placental transfer or postnatally when exposed through breast milk (numerous agents— see Some Drugs Contraindicated for Breastfeeding Mothers and see Table: Some Drugs Contraindicated for Breastfeeding Mothers). Because there are limited data regarding the potential for drug exposure during pregnancy and lactation, the 21st Century Cures Act established a task force to identify gaps in knowledge and research on safe and effective therapies for pregnant women and lactating women (1).
2). Current recommendations are that over-the-counter cough and cold preparations should not be given to children < 4 years old, and should be given cautiously to children 4 to 6 years old.
Adverse effects and toxicity references
1. The Task Force on Research Specific to Pregnant Women and Lactating Women: Report to Secretary, Health and Human Services, Congress. September 2018.
2. Halmo LS, Wang GS, Reynolds KM, et al: Pediatric fatalities associated with over-the-counter cough and cold medications. Pediatrics 148(5):e2020049536, 2021. doi: 10.1542/peds.2020-049536
More Information
The following English-language resources may be useful. Please note that THE MANUAL is not responsible for the content of these resources.
U.S. Food and Drug Administration (FDA): Best Pharmaceuticals for Children Act and Pediatric Research Equity Act status report (2020)
American Academy of Pediatrics: Codeine: Time to Say “No”
