Pediatric and geriatric Flashcards
(35 cards)
What physiologic processes influence pharmacokinetics in infants?
Physiologic processes that influence pharmacokinetic variables change significantly in the first year of life, particularly during the first few months.
What are the unique factors influencing drug absorption in infants?
Factors include blood flow at the site of administration and gastrointestinal function.
What influences absorption after IM or SC injection in neonates?
Absorption depends mainly on the rate of blood flow to the muscle or subcutaneous area injected.
What can reduce blood flow affecting drug absorption in neonates?
- Cardiovascular shock
- Vasoconstriction due to sympathomimetic agents
- Heart failure
How does gastric acid secretion differ between full-term and preterm infants?
In full-term infants, gastric acid secretion begins soon after birth and increases gradually, while in preterm infants, it occurs more slowly.
What is the gastric emptying time in neonates?
Gastric emptying time is prolonged (up to 6 or 8 hours) in the first day after delivery.
What are the effects of irregular peristalsis in neonates on drug absorption?
Irregular peristalsis may lead to unpredictable absorption and potential toxicity.
What is the typical water percentage of body weight in neonates compared to adults?
Neonates have 70–75% body weight as water, while adults have 50–60%.
How does drug binding to plasma proteins differ in neonates?
Protein binding of drugs is reduced in neonates, increasing the concentration of free drug in plasma.
What is the significance of cytochrome P450 in drug metabolism in neonates?
Cytochrome P450-dependent mixed-function oxidases and conjugating enzymes are substantially lower in early neonatal life.
What is the glomerular filtration rate (GFR) in neonates compared to adults?
GFR in neonates is only 30–40% of adult value.
What is the effect of renal function on drug clearance in toddlers?
Toddlers may have shorter elimination half-lives of drugs than older children and adults due to increased renal elimination.
What is a common dosage adjustment for ampicillin in neonates less than 7 days old?
50–100 mg/kg/d in two doses at 12-hour intervals.
What is the effect of indomethacin in neonates?
Indomethacin causes the rapid closure of a patent ductus arteriosus.
What challenges exist in compliance for pediatric drug administration?
Challenges include measuring errors, spilling, and spitting out medications.
What is the most reliable source for pediatric dose information?
The package insert provided by the manufacturer.
What changes occur in body composition as people age?
Elderly have reduced lean body mass, reduced body water, and increased fat.
How does aging affect drug metabolism?
The capacity of the liver to metabolize drugs does not decline consistently with age; phase I reactions show the greatest changes.
What is a key renal function change in the elderly?
There is a decline in renal functional capacity, particularly in creatinine clearance.
What should be considered when dosing elderly patients?
Dosing recommendations often include an allowance for reduced renal clearance.
True or False: Geriatric patients are much more sensitive to all drugs than younger patients.
False
Fill in the blank: The liver’s ability to recover from injury is ______ in elderly patients.
decreased
What is the significance of serum creatinine in assessing renal function in the elderly?
Serum creatinine alone is not an adequate measure of renal function due to reduced muscle mass.
Why is serum creatinine alone not an adequate measure of renal function in the elderly?
Serum creatinine declines with age, necessitating dosing recommendations that account for reduced renal clearance.
Cockcroft-Gault formula is often used for estimating renal function in elderly patients.
