Individual Variations & Age Considerations Flashcards
Define pharmacodynamic tolerance
- Occurs when the intrinsic responsivity of the receptor system diminishes over time. What most people think of with drug tolerance, like with opiods and alcohol. Need to keep upping the dose to get the same initial response.
Define metabolic tolerance
- Occurs when the body metabolizes drugs at an accelerated rate.
Define tachyphylaxis
- Occurs when response from a drug decreases with repeated dosing (ie Nitroglycerin). Needs to be a drug-free period of time for the body to rebuild effectiveness.
Any response a patient has to a _________ is based solely on patient’s psychological reaction to the idea of taking the medication.
Placebo
Define pharmacogenomics
The study of how genes affect individual drug responses
Most research done in pharmacogenomics is related to _________ pathways.
CYP450
Name the 3 types of CYP phenotypes that get tested for within pharmacogenetics.
Ultra rapid metabolizers, extensive metabolizers, and poor metabolizers
Which type of phenotype represents normal metabolism?
Extensive metabolizers
When an active drug is administered to an ultrarapid metabolizer, what happens?
Decreased effect
When a prodrug drug is administered to an ultrarapid metabolizer, what happens?
Increased toxicity
When an active drug is administered to an extensive metabolizer, what happens?
Normal reaction
When a prodrug drug is administered to an extensive metabolizer, what happens?
Normal reaction
When an active drug is administered to an poor metabolizer, what happens?
Increased toxicity
When a prodrug drug is administered to an poor metabolizer, what happens?
Decreased effect
Alcohol is metabolized more __________ by women than men.
Slowly
Quinidine causes greater QT interval prolongation in _______.
Women
Some reasons for lack of adherence to drug regimens:
- Belief the drug will not work and concern as to whether they even need it
- Manual dexterity
- Visual acuity
- Intellectual ability
- Psychological state
- Attitude toward drugs
- Ability to pay
- Drug-drug interactions
- Drug-food interactions
____ % of folks do not take meds as prescribed.
30-60%
When in pregnancy is renal blood flow doubled and renal excretion accelerated?
Third trimester
T/F: Medicine does not cross the placental barrier
False
What drugs cross the placental barrier?
ALL OF THEM
Which drugs cross the placental barrier easiest?
Lipid soluble
Name three types of drugs that don’t cross the placental barrier as easily
Protein-bound, ionized, polar
What is the process by which congenital malformations are produced in an embryo or fetus?
Teratogenesis
What percentage of all birth defects are caused by drugs?
1%
What percentage of all birth defects are caused by genetics?
25%
Name 3 contributing factors to drug contribution of teratogenesis.
- Stage of development of the embryo/fetus
- Amount of drug ingested
- Frequency of ingestion
When is the embryo/fetus the most vulnerable/susceptible to drugs during development?
Conception - week 2
and embryonic period (weeks 3-8)
What is occurring that can cause gross malformations during the first two weeks of embryo development?
Organ development
Name three ways to decrease the risk to an infant when the mother is taking medications while breastfeeding.
- Take drugs immediately after breastfeeding
- Avoid drugs with a long half-life
- Choose drugs that tend to be excluded from milk and are least likely to affect infant
- Avoid sustained released drugs
- Avoid hazardous drugs (duh)
Name 3 things that increase the risk of a medication to an infant while breastfeeding.
- Fat solubility
- Oral bioavailability
- Half life
Name 3 things that decrease the risk of a medication to an infant while breastfeeding.
- Molecular size
- Protein-binding ability
- Acidity
Name other physiological changes that occur during pregnancy that impact drug absorption.
- Increased renal blood flow
- Increase hepatic metabolism
- Decreased tone and mobility of bowel (= prolonged transit = increased absorption)
What are two ways to gather data about whether drugs are safe during pregnancy?
- Drug registry (someone is put on a drug and they will hopefully join the registry. This is different from a baby shower registry. A lot different.)
- Retrospective studies
How do we know drugs are safe during pregnancy?
WE DON’T
What are the 5 letter risk categories that were devised by the FDA in 1979 (for drug safety during pregnancy)?
A, B, C, D, and X
Which of the 5 FDA letter risk categories for drug safety during pregnancy is the one that is least dangerous?
A
Which 2 of the 5 FDA letter risk categories for drug safety during pregnancy are the ones that are the most dangerous?
D and X
What is the new labeling the FDA came up with in 2020?
Risk summary, narrative sections and subsections that seem infinitely more confusing
Pediatrics have a higher/lower risk of adverse drug reactions?
Higher
T/F: Half of all drugs in peds have never been tested
False: 2/3!!
What are the two ways most commonly used to dose medications for pediatrics?
- Weight
- BSA (body surface area)
What is the Body Surface Area (BSA) math for pediatric dosing?
BSA of child x adult dose / 1.73 m^2
What is the weight math for pediatric dosing?
mg/kg/day q 12 hr
