Chapter 3 Flashcards
What are the 4 life span considerations?
Pregnancy
Breast-feeding
Neonatal and Pediatric
Elderly
In pregnancy the _____ trimester is the period of greatest danger for drug-induced developmental defects
First
Drugs cross the placenta by
Diffusion
During the _____ trimester the greatest % of maternally absorbed drug gets to the fetus
last
What are the categories of the pregnancy safety categories?
A B C D X
Category A
Safest - no risk
Adequate and well-controlled studies have failed to demonstrate a risk
to the fetus in the first trimester of pregnancy (and there is no evidence
of risk in later trimesters)
Category B
No risk to fetus - not available for humans
Animal reproduction studies have failed to demonstrate a risk to the
fetus and there are no adequate and well-controlled studies in pregnant
women.
Category C
Animal reproduction studies have shown an adverse effect on the fetus
and there are no adequate and well-controlled studies in humans, but
potential benefits may warrant use of the drug in pregnant women
despite potential risks
Category D
There is positive evidence of human fetal risk based on adverse
reaction data from investigational or marketing experience or studies
in humans, but potential benefits may warrant use of the drug in
pregnant women despite potential risks.
Category X
Studies in animals or humans have demonstrated fetal abnormalities
and/or there is positive evidence of human fetal risk based on adverse
reaction data from investigational or marketing experience, and the
risks involved in use of the drug in pregnant women clearly outweigh
potential benefits
Breast-fed infants are at risk for exposure to _____ consumed by the mother
drugs
What are the 3 absorption for neonatal and pediatric considerations in pharmacokinetics?
Gastric pH less acidic
Gastric emptying is slowed
Intramuscular absorption faster and irregular
What are the 4 distribution for neonatal and pediatric considerations in pharmacokinetics?
The younger the person, the greater the % of total body water
Greater TBW means fat content is lower
Decreased level of protein binding
Immature blood-brain barrier - more drugs enter the brain
What are the 2 metabolism for neonatal and pediatric considerations in pharmacokinetics?
Liver immature, does not produce enough microsomal enzymes
Oder children may have increased metabolism requiring higher dose than infants
What are the 2 excretion for neonatal and pediatric considerations in pharmacokinetics?
Kidney immaturity affects glomerular filtration rate and tubular secretion
Decreased perfusion rate of the kidneys may reduce excretion of drugs
What are the factors affecting pediatric drug dosages
Skin is thin and permeable
Stomach lacks acid to kill bacteria
Lungs have weaker mucus barriers
Body temperatures less well regulated and dehydration occurs easily
Liver and kidneys are immature, impairing drug metabolism and excretion
The 2 methods of calculation for pediatric patients
Body surface area - scientific - Using the West nomogram
Body weight dosage calculations - common - Using mg/kg
What age group is considered elderly?
Older then 65
What are the 4 physiologic changes in the elderly patients?
Cardiovascular
Gastrointestinal
Hepatic
Renal
What are the absorption for the elderly in pharmacokinetics?
Gastric pH less acidic Gastric emptying slowed Movement through GI tract slowed Blood flow to GI tract reduced Use of laxatives may accelerate GI motility
What are the distribution for the elderly in pharmacokinetics?
Lower total body water %
Increase fat content
Decreased production of proteins by the liver, resulting in decreased protein binding of drugs
What are the metabolism for the elderly in pharmacokinetics?
Aging liver produces fewer microsomal enzymes, affecting drug metabolism
Reducing blood flow to the liver
What are the excretion for the elderly in pharmacokinetics?
Decreased glomerular filtration rate
Decreased number of intact nephrons
When calculating pediatric dosages, what will the nurse take into consideration?
Dosage calculation by body surface area is the most accurate method because it takes into account the difference in size of the child and/or neonate.
When teaching a pregnant mother about the effects of medication on the fetus, the nurse recognizes that the greatest harm from maternally ingested medications occurs during which time period?
First trimester
Knowing that the albumin in neonates and infants has a lower binding capacity for medications, a health care provider would do which of the following to minimize the risk of toxicity?
Decrease the amount of drug given
The physiologic changes that normally occur in the older adult have which of the following implications for the nurse who is assessing drug response in this patient?
Drug half-life is lengthened
The nurse is admitting an 82-year-old patient for treatment of heart failure. During assessment of the patient’s history, the nurse notes a subjective complaint of chronic constipation. Of the prescribed medications the patient was taking prior to admission, which would the nurse suspect might contribute to this gastrointestinal complaint?
verapamil (Calan), a calcium channel–blocking drug
The nurse working in a prenatal clinic recognizes that the safety or potential harm of drug therapy during pregnancy relates to which factor?
Drug properties
A mother of a 1-month-old infant calls the clinic and asks the nurse if the medication she is taking can be passed to her infant during breast-feeding. What is the appropriate response for this patient?
“Drugs can cross from mother to infant in breast milk, so it will depend on the drug you are taking.”
A nurse working with elderly patients is concerned with the number of medications each patient is taking. Which will the nurse assess as highest priority for her patients related to polypharmacy?
Drug interactions
