Walden university nrnp 6566 midterm exam study
guide with complete solution
NRNP 6566 vl
Key Concepts Week 1 to 5 vl vl vl vl vl
Week 1
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1. Describe the cytochrome P450 system. Describe how inducers and inhibitors affect the
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cytochrome system and how that affects the half-life of medications.
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a. Cytochrome p450 system is a series of enzymes used to metabolize medications. vl vl vl vl vl vl vl vl vl vl vl
b. Drugs that cause CYP450 metabolic drug interactions are referred to as either inhibitors
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or inducers. Inducers increase CYP450 enzyme activity by increasing enzyme
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synthesis vl
c. Inhibitors block the metabolic activity of one or more CYP450 enzymes vl vl vl vl vl vl vl vl vl vl
2. Describe the affect on low and high albumin levels on active drug levels especially for drugs
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that are highly protein bound.
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a. Albumin is the plasma protein with the greatest capacity for binding drugs. vl vl vl vl vl vl vl vl vl vl vl
i. Binding to plasma proteins affects drug distribution into tissues, because only vl vl vl vl vl vl vl vl vl vl
drug that is not bound is available to penetrate tissues, bind to receptors, and
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exert activity. As free drug leaves the bloodstream, more bound drug is released
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from binding sites. vl vl vl
b. Highly protein bound drugs, low albumin levels (w/ malnutrition, or chronic illness) may
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lead to toxicity because there are fewer than the normal sites for the drug to bind
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3. Describe ways to lessen the hepatic first pass effect: metabolism during first pass through the
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liver
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a. Alternative routes (suppository, intravenous, intramuscular, inhalational aerosol, vl vl vl vl vl vl
transdermal, and sublingual) avoid the first-pass effect allow drugs to be absorbed
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directly into the systemic circulation
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4. Be able to calculate creatinine clearance using the Cockgraft Gault equiation:
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a. Male = ([140-age] × weight in kg)/(serum creatinine × 72)
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b. Female = CrCl (male) × 0.85 vl vl vl vl vl vl
5. Describe what determines the frequency of drug administration:
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a. Drug half-life, plasma concentration vl vl vl
6. Be familiar with the Beers criteria and how to use it:
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a. Potentially Inappropriate Medication Use in Older Adults vl vl vl vl vl vl
i. to call attention to medications that are commonly problematic, and thus should
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be avoided in most older adults vl vl vl vl vl vl
7. Describe factors that affect absorption, distribution, metabolism and excretion:
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a. Absorption low blood state (shock or arrest); contact time with GI tract too fast vl vl vl vl vl vl vl vl vl vl vl vl vl vl
, (diarrhea = can’t absorb); delayed stomach emptying (large meal = delayed absorption);
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drug-drug or drug-food interactions
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b. Metabolism genetics, age, organ function
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c. Distribution low albumin levels, body composition, cardiac decomp (HF), and age
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d. Excretion affected by abnormal kidney or liver function; age, drug interactions
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8. Define narrow therapeutic index How would you monitor a patient with a narrow therapeutic
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index?
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, a. Therapeutic index: dose range where efficacy of med is optimized while side effects vl vl vl vl vl vl vl vl vl vl vl vl
minimized
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b. Narrow therapeutic index (NTI) drugs are defined as those drugs where small
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differences in dose or blood concentration may lead to dose and blood concentration
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dependent, serious therapeutic failures or adverse drug reactions.
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c. Blood tests to monitor blood concentrations and dose adjustments accordingly
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9. Describe how aging affect absorption, distribution, metabolism, and excretion
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a. Decreased organ function, poorly tolerate drugs that require metabolism, lower rates of
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excretion
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b. decrease in small-bowel surface area, slowed gastric emptying, and an increase in
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gastric pH, changes in drug absorption
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c. With age, body fat generally increases and total body water decreases. Increased fat
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increases the volume of distribution for highly lipophilic drugs
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(eg, diazepam, chlordiazepoxide) and may increase their elimination half-lives.
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d. Serum albumin decreases and alpha 1-acid glycoprotein increases
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i. Phenytoin and warfarin are examples of drugs with a higher risk of toxic effects vl vl vl vl vl vl vl vl vl vl vl vl vl
when the serum albumin level decreases
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e. hepatic metabolism of many drugs through the cytochrome P-450 enzyme system
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decreases with age. For drugs with decreased hepatic metabolism clearance typically
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decreases 30 to 40%.
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i. Drugs metabolized in phase 1 reactions likely prolonged vl vl vl vl vl vl vl
ii. First-pass metabolism (metabolism, typically hepatic, that occurs before a drug vl vl vl vl vl vl vl vl vl
reaches systemic circulation) decreasing by about 1%/yr after age 40.
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1. Thus, for a given oral dose, older adults may have higher circulating drug vl vl vl vl vl vl vl vl vl vl vl vl
concentrations. vl
f. Decreased renal elimination vl vl
Week 2 and 3
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1. Identify and describe 12 lead EKGs that demonstrate:
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a. 1st, 2nd, and 3rd degree AV blocks
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i. 1st degree HB cards consult vl vl vl
ii. 2nd degree HB type 1 & 2 vl vl vl vl vl vl vl
1. Type 1: Echo (r/o structural dx), Thyroid levels, meds, lytes to identify and vl vl vl vl vl vl vl vl vl vl vl vl
treat cause vl vl
2. Type 2: PPM, continuous tele with transcutaneous pacing if needed, vl vl vl vl vl vl vl vl vl
determine cause; IV atropine if poor perfusion s/s q 3-5m with max 3mg if vl vl vl vl vl vl vl vl vl vl vl vl vl vl
s/s poor perfusion; vl vl vl
3. If no response to atropine dopa, epi, isoproterenol vl vl vl vl vl vl vl
rd
iii. 3 degree/ complete HB: PPM; tele and transcutaneous pace if neded; identify
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cause; IV atropine if s/s poor perfusion; If no response to atropine dopa, epi,
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isoproterenol vl
b. STEMI in any lead (know what area of the heart is affected based on lead location)
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c. Atrial fibrillation: vl
