CHAPTER 3.docx

CHAPTER 3 Lifespan considerations have dramatic effects of the four phases of pharmacokinetics. Absorptions in peds patients is altered due to a gastric PH less acidic until 1-2 years of age. Absorptions in peds patients is altered due to gastric emptying being slowed. In pediatric patients, first-...

CHAPTER 3 Lifespan considerations have dramatic effects of the four phases of pharmacokinetics. Absorptions in peds patients is altered due to a gastric PH less acidic until 1-2 years of age. Absorptions in peds patients is altered due to gastric emptying being slowed. In pediatric patients, first-pass elimination is reduced due to an immature liver. In pediatric patients, intramuscular absorption is faster and irregular. Distribution in pediatric patients is affected by greater total body water meaning lower fat content and decreased level of protein binding. Pediatric patients can have more side effects due to immature blood-brain barrier which means more drugs enter the brain. Pediatric patients’ metabolism is altered due to liver immaturity which causes it to not produce enough microsomal enzymes. Older children may require higher doses of medication due to increased metabolism. Excretion in peds patients is affected by kidney immaturity. Factors affecting pediatric drug doses are: Skin is thin Stomach lacks bacteria killing acid Lungs have weaker mucous barriers Body temperatures can’t regulate as well and dehydration occurs easily. Liver and kidneys are immature. When working with pediatric patients, make sure you prepare all equipment and supplies first and have their parents stay as appropriate. With pediatric patients, assess for comfort methods before, during, and after drug administration. Decline in organ function occurs with advancing age. Drug therapy in older adults is most likely to result in adverse effects and toxicity. Absorptions is older adult patients is altered due to gastric ph being less acidic and slowed GI function. Distribution in older adult patients is affected by lower total body water percentages, increased fat content, and decreased liver protein production. Older adult patients metabolism is altered due to aging liver and reduced blood flow to the liver. Excretion in older adult patients is affected by decreased glomerular filtration rate and decreased number of nephrons causing drugs to be cleared less effectively.