Neonatal, pediatric, and lactation pharm Flashcards
How does drug absorption change after birth
There are some transient changes in gastrointestinal absorption of drugs immediately after birth related to changes in the speed of intestinal and gastric peristalsis and the ramping up of gastric acid secretion. In addition, pancreatic enzymatic secretions are not at full potential for several weeks two months following delivery, so the absorption of fat soluble medications maybe decreased in this age group compared to older children and adults. These factors are taken into account with the recommended doses and dosing intervals in this age group.
Neonates have a much ____ percentage of body weight in the form of water (___) than do adults (____).
Neonates have a much higher percentage of body weight in the form of water (70 to 75%) than do adults (50 to 60%).
Extracellular water in neonate
extracellular water is 40% of the bodyweight in the neonate compared with 20% in the adult. Most neonates will diuresce (pee off) water significantly in the first 24-48 hours of life.
Physiological differences in preterm infants
Preterm infants have much less fat than full term infants, as low as 1% of total body weight compared with 15% and full-term babies. Therefore, organs that generally accumulate high concentrations of lipophilic drugs may accumulate much smaller amounts of these agents in preterm infants. All of these factors result in body surface area, rather than kg of mass, being recommended to estimate best effective dose in babies for critical situations where the exact right dose is essential (the PICU, the OR, etc.)
Protein binding in newborns
In general, protein binding of drugs is reduced in newborns. Therefore, the concentration of free drug in the plasma is generally increased. Because the free drug increases the gradient to move into tissue and bind to the target receptor, this can result in either greater drug effect than desired or toxicity.
Drug interactions with neonatal bilirubin and albumin
Drugs can cause displacement of bilirubin from albumin when the drug has a higher affinity for albumin than bilirubin’s affinity for albumin. If a substantial amount of bilirubin is displaced, unconjugated bilirubin may enter the neonatal brain and cause kernicterus. This was observed in preterm infants when sulfonamide antibiotics were given into that population to prevent neonatal sepsis, and is the reason why sulfa drugs are listed as contraindicated for infants under six months of age.
The reverse is also true, meaning that a jaundiced infant can have a high enough bilirubin that bilirubin displaces a drug bound to albumin, raising the free drug concentration.
Liver metabolism in infants
babies have significantly lower activities in liver enzyme systems when they are first born than expected levels for older children and adults. Maturation of some of these enzyme systems occurs between the third and fourth years of life
GFR differences in neonates and toddlers
The glomerular filtration rate is much lower for the first few days of life. In fact, by unit of body surface area, glomerular filtration in the neonate is only 30 to 40% of the adult values. This difference is even more significant for preterm babies. In contrast, during toddlerhood, GFR exceeds adult values again potentially requiring larger doses per kilogram than adults would be able to clear
mLs of teaspoon and tablespoon
When we say “teaspoon”, what we mean is 5 mLs.
When we say “tablespoon”, what we mean is 15 mLs.
What drugs are contraindicated for lactating mothers
chemotherapeutic, cytotoxic, or immunomodulator drugs other than low doses of prednisone are
Dosing strategy to make lactation safer
take the drug 30 to 60 minutes after nursing and 3 to 4 hours before the next feeding,
Caffeine and lactation
caffeine taken at normal doses via coffee or other drinks is safe in lactation
Drugs to avoid when lactating
