BIO200H5 Lecture Notes - Lecture 19: Chloramphenicol, Acid Dissociation Constant, Pharmacokinetics
Document Summary
Drug response in infants and old people differs from drug response in young adults, due to differences in: pharmacokinetics, pharmacodynamics. These are important considerations in pediatric and geriatric drug therapy. Gastric ph: newborns to 3 yrs: low gastric acidity (ph 6-8, ph in small intestine is also higher ph influences - chemical stability e. g. penicillin g. Drug absorption (pka basic drugs less charged) Gastric emptying: slower in newborns (< 1 yr) Gut motility: irregular and unpredictable, may affect - overall rate of absorption. Plasma protein-binding of many drugs is less in newborns: total plasma protein is lower: albumin. 1-acid glycoprotein: also, the bbb is immature in newborns, kernicterous: the low plasma protein and immature bbb plus a deficieny in drug conjugation (below) - can lead to a brain damage syndrome. There are high concentrations of bilirubin (a breakdown product of fetal red blood cells) in newborn plasma.
