NRNP 6566 MIDTERM EXAM
Describe cytochrome p450 system - ANSWER Cytochrome p450 system is a series
of enzymes used to metabolize medications
Inhibitors - ANSWER block metabolic activity from one or more CYP450 enzymes
Inducers - ANSWER increase CYP450 enzyme activity by increasing enzyme
synthesis
Describe effect on low and high albumin levels on active drug levels especially for
drugs that are highly protein bound - ANSWER Albumin is the plasma protein with
the greatest capacity for binding drugs. Binding plasma proteins affect drug
distribution into tissues, because only drug that is not bound is available to penetrate
tissues, bind to receptors, and exert activity. As free drug leaves the blood stream,
more bound drug is released from binding sites.
Low albumin levels - ANSWER malnutrition, chronic illness
Highly protein bound drugs can lead to - ANSWER toxicity in patients with low
albumin levels, example malnutrition or chronic illness. This is because there are
fewer than the normal sites for the drug to bind
Describe the ways the hepatic first pass effect- which is metabolism during first pass
through the liver - ANSWER Alternative routes include:
suppository
intravenous
intramuscular
inhalational aerosol
transdermal
sublingual
These allow drugs to bypass the first-pass effect and be absorbed directly into
systemic circulation
Be able to calculate creatinine clearance using Cockgraft Gault equation: - ANSWER
Male = 140-age times weight in kilograms divided by serum creatinine times 72.
Women = CRCL (male) times 0.85
Describe what determines the frequency of drug administration - ANSWER half life
plasma concentration
Be familiar with the beers criteria and how to use it - ANSWER Potentially
Inappropriate Medication Use in Older Adults
to call attention to medications that are most commonly problematic and thus should
be avoided in older adults
, Describe factors that affect absorption - ANSWER low blood state (shock or arrest),
contact time with GI tract too fast (diarrhea = cant absorb), delayed stomach
emptying (large meal = delayed absorption)Drug- to drug or drug to food interactions
Describe the factors that affect distribution - ANSWER low albumin levels, body
composition, cardiac decompensation (heart failure), age
Describe the factors that affect metabolism - ANSWER genetics, age, organ
function
Describe factors that affect excretion - ANSWER affected by abnormal kidney or
liver function, age, drug interactions
Define narrow therapeutic index. How would you monitor a patient with a narrow
therapeutic index? - ANSWER Therapeutic index is the dose range of effiency of
med is optimized while side effects are minimized
Narrow therapeutic index drugs are defined as those drugs where small differences
in dose or blood concentration may lead to dose and blood concentration dependant,
serious therapeutic failures or adverse drug reactions.
You will need to monitor blood tests to monitor blood concentrations and dose
adjustments accordingly.
Describe how aging can affect absorption, distribution, metabolism and excretion -
ANSWER decreased organ function, poorly tolerate drugs that require metabolism,
lower rates of excretion
decrease in small-bowel surface area, slowed gastric emptying, increase in gastric
PH, changes in drug absorption
With age, body fat generally increases and total body water decreases. Increased fat
increases the volume of distribution for highly lipophilic drugs (for example,
diazepam and chlordiazepoxide), which may increase their elimination half-lives.
Serum albumin decreases and alpha 1 acid glycoprotein increases -- Phenytoin and
warfarin are examples of medications with a higher risk of toxic effects when serum
albumin increases
hepatic metabolism of many drugs through cytochrome P enzyme system decreases
with age; decreasing 30-40%
decreased renal elimination
Identify 1st degree heart block - ANSWER cardiologist consult
Order echo to rule out structural diagnosis, check thyroid levels, medications,
electrolytes and identify and treat cause
Identify 2nd degree heart block - ANSWER permanent pacemaker, continuous tele
monitoring, possible transcutaneous pacing, determine cause; IV atropine if poor
perfusion s/s every 3-5 minutes with max of 3mg if poor perfusion. No response to
atropine, use dopamine, epinephrine, isoproterenol
Identify 3rd degree heart block/complete heart block - ANSWER Permanent
pacemaker, telemetry monitoring and transcutaneous pacing if needed, identify
cause, IV atropine if s/s poor perfusion. If no response to atropine, use dopamine,
epinephrine and isoproterenol
Describe cytochrome p450 system - ANSWER Cytochrome p450 system is a series
of enzymes used to metabolize medications
Inhibitors - ANSWER block metabolic activity from one or more CYP450 enzymes
Inducers - ANSWER increase CYP450 enzyme activity by increasing enzyme
synthesis
Describe effect on low and high albumin levels on active drug levels especially for
drugs that are highly protein bound - ANSWER Albumin is the plasma protein with
the greatest capacity for binding drugs. Binding plasma proteins affect drug
distribution into tissues, because only drug that is not bound is available to penetrate
tissues, bind to receptors, and exert activity. As free drug leaves the blood stream,
more bound drug is released from binding sites.
Low albumin levels - ANSWER malnutrition, chronic illness
Highly protein bound drugs can lead to - ANSWER toxicity in patients with low
albumin levels, example malnutrition or chronic illness. This is because there are
fewer than the normal sites for the drug to bind
Describe the ways the hepatic first pass effect- which is metabolism during first pass
through the liver - ANSWER Alternative routes include:
suppository
intravenous
intramuscular
inhalational aerosol
transdermal
sublingual
These allow drugs to bypass the first-pass effect and be absorbed directly into
systemic circulation
Be able to calculate creatinine clearance using Cockgraft Gault equation: - ANSWER
Male = 140-age times weight in kilograms divided by serum creatinine times 72.
Women = CRCL (male) times 0.85
Describe what determines the frequency of drug administration - ANSWER half life
plasma concentration
Be familiar with the beers criteria and how to use it - ANSWER Potentially
Inappropriate Medication Use in Older Adults
to call attention to medications that are most commonly problematic and thus should
be avoided in older adults
, Describe factors that affect absorption - ANSWER low blood state (shock or arrest),
contact time with GI tract too fast (diarrhea = cant absorb), delayed stomach
emptying (large meal = delayed absorption)Drug- to drug or drug to food interactions
Describe the factors that affect distribution - ANSWER low albumin levels, body
composition, cardiac decompensation (heart failure), age
Describe the factors that affect metabolism - ANSWER genetics, age, organ
function
Describe factors that affect excretion - ANSWER affected by abnormal kidney or
liver function, age, drug interactions
Define narrow therapeutic index. How would you monitor a patient with a narrow
therapeutic index? - ANSWER Therapeutic index is the dose range of effiency of
med is optimized while side effects are minimized
Narrow therapeutic index drugs are defined as those drugs where small differences
in dose or blood concentration may lead to dose and blood concentration dependant,
serious therapeutic failures or adverse drug reactions.
You will need to monitor blood tests to monitor blood concentrations and dose
adjustments accordingly.
Describe how aging can affect absorption, distribution, metabolism and excretion -
ANSWER decreased organ function, poorly tolerate drugs that require metabolism,
lower rates of excretion
decrease in small-bowel surface area, slowed gastric emptying, increase in gastric
PH, changes in drug absorption
With age, body fat generally increases and total body water decreases. Increased fat
increases the volume of distribution for highly lipophilic drugs (for example,
diazepam and chlordiazepoxide), which may increase their elimination half-lives.
Serum albumin decreases and alpha 1 acid glycoprotein increases -- Phenytoin and
warfarin are examples of medications with a higher risk of toxic effects when serum
albumin increases
hepatic metabolism of many drugs through cytochrome P enzyme system decreases
with age; decreasing 30-40%
decreased renal elimination
Identify 1st degree heart block - ANSWER cardiologist consult
Order echo to rule out structural diagnosis, check thyroid levels, medications,
electrolytes and identify and treat cause
Identify 2nd degree heart block - ANSWER permanent pacemaker, continuous tele
monitoring, possible transcutaneous pacing, determine cause; IV atropine if poor
perfusion s/s every 3-5 minutes with max of 3mg if poor perfusion. No response to
atropine, use dopamine, epinephrine, isoproterenol
Identify 3rd degree heart block/complete heart block - ANSWER Permanent
pacemaker, telemetry monitoring and transcutaneous pacing if needed, identify
cause, IV atropine if s/s poor perfusion. If no response to atropine, use dopamine,
epinephrine and isoproterenol
