Unraveling Pharmacokinetics and Pharmacodynamics in Infants and Children

Abstract

Our knowledge of the pharmacology of the drugs used in pediatric anesthesia has advanced with a greater understanding of their pharmacokinetics (PK) and pharmacodynamics. This has resulted in a refinement of their uses, broader indications, and alternative methods of delivery. For example, methadone is becoming increasingly popular for spinal surgery, the dosing of etomidate has been clarified and the PK of intravenous acetaminophen from neonates to adults has been revealed. Morphine PK have also been clarified, although pharmacodynamic ethnic differences remain unexplained. The optimal size descriptor to predict correct drug doses in the obese remains controversial. Efforts to reduce adverse effects of individual drugs have spawned investigations into beneficial drug interactions, although combinations such as propofol and ketamine await PK and safety review. The nasal route may be a reasonable alternative to intravenous administration for many drugs. Oral ketamine may serve as a valuable premedication for children suffering burns. Expanded indications can have unfavorable consequences; propofol may cause profound hypotension in neonates.