Pharmacology, RSNG 1301, Chapter 5 Objectives- Questions and Answers

1. Identify key characteristics of pediatric pharmacotherapy in children from birth to 18 years of age. Key characteristics of pediatric pharmacotherapy include: doses are calculated based on the patient’s weight ; effec tiveness of medication in pediatrics varies due to physiological difference across developmental levels; variability in pharmacodynamics is related to total body water, fat stores and immature organ systems - these differences in pediatrics versus adults results in varied pharmacokinetics after drug administration. (Page 76) 2. Describe the evolution of pediatric pharmacotherapy and the purpose of federal legislation in the development of current practice standards. In the past, researchers only tested drugs on adults, resulting in prescribers to assume that a smaller dose would elicit the same response as with an adult. However, throughout the last few decades, the FDA has pushed for the pharmaceutical industry to submit all knowledge about medication for children . After this, the FDA began passing acts that will provide incentives for companies who research the safety of medications for children. With the research showing gaps in the knowledge for pharmacotherapy in children, the Food and Drug Administration Safety and Innovation Act (FDASIA) was enacted to provide an overview of laws and regulations for the pediatric program and suggestions for improving pediatric research. (Page 71) 3. Describe methods for determining accurate pediatric dosing. Determining a pediatric dose is based solely on their weight. A provider can also u se the child’s height and weight, t o calculate the BSA for the patient (there are averages for certain age groups). The BSA can then be plugged into this equation: 𝑃𝑒𝑑𝑖𝑎𝑡𝑟𝑖𝑐 𝐷𝑜𝑠𝑒=𝐵𝑆𝐴 1.73 × 𝐴𝑑𝑢𝑙𝑡 𝐷𝑜𝑠𝑒 ⁄ (Page 71) 4. Explain differences in pharmacodynamic variables between children and adults. Because children have immature organ systems and changing body composition (total body water, fat stores and protein levels) can affect the drug action on the target cells differently than that of adults. (Page 72) 5. Explain pharmacokinetic differences between children and adults. Absorption: Age of the child, gastric emptying, intestinal motility, routes of administration, and skin permeability all affect drug absorption in pediatrics. Neonates have irregular gastric emptying which can result in increased drug levels. They also have reduced gastric acidity which can result in greater or weaker absorption of aci d-labile or weakly acidic medications. Pediatric patients can have unpredictable absorption of intramuscular medications due to the lack of blood flow to skeletal muscles and weak muscle contractions. Thinner skin in pediatric patients can increase the rate of absorption of topical medications. (Page 72) Distribution: In pediatric patients, the distribution of a drug is dependent upon percentage of body water, liver function, degree of protein binding and the development of the blood brain barrier. Because neonates and premature infants have a higher total body water percentage, water -soluble drugs are diluted easily and can cause a lower serum drug concentration. Due to an