Therapeutic drug serum levels narrow range of medication in bloodstream, for desired results; clinical status of patient is appropriate for condition; peak and trough levels (measured by serum blood levels)
nontherapeutic drug serum levels can be either: undertherapeutic or toxic
toxic drug serum...
NUR 3145 Exam 1 Practice Questions
and Solutions
Therapeutic drug serum levels ✅narrow range of medication in bloodstream, for
desired results; clinical status of patient is appropriate for condition; peak and trough
levels (measured by serum blood levels)
nontherapeutic drug serum levels can be either: ✅undertherapeutic or toxic
toxic drug serum levels ✅greater than therapeutic dose range; increased adverse
effects
under-therapeutic drug serum levels ✅not enough drug for desired effect; may
contribute to drug-resistant organisms
o Drug Bioavailability ✅% of active drug absorbed that reaches target tissues
o Drug Bioavailability: determinants ✅route/form of drug; blood flow; liver/kidney
function; acid-base environment; presence of food, resident bacteria, motility in GI tract;
presence of pain/stress; other drugs
o Oral Absorption (PO): ✅absorbed from GI tract to body tissues; slower
-Diffuses across cell membrane; assisted by carrier enzymes or proteins; engulfed by
cellular membranes (pinocytosis)
-Easier, more convenient, less expensive; safer than injection; dosage easier to
reverse through intervention in case of accident
o Parenteral Absorption: ✅by injection; bypass GI tract
Intravenous ✅absorbed directly into bloodstream
• Rapid onset, since drug is administered directly to bloodstream
• Allows for more direct control of drug level in blood; Gives option of larger fluid volume,
therefore diluting irritating drugs
• Avoids first-pass metabolism
Intramuscular ✅: absorbed from blood supply of muscles
• Good for poorly soluble drugs, often given in "depot" preparation form and then
absorbed over a long period of time
• Onsets of action depend on route
Subcutaneous: ✅absorbed through capillaries
• Same benefits as IM
,o Other routes:
Topical ✅: transdermal
• Delivers medication directly to affected area; decreases likelihood of systemic drug
effects
o Other routes: Inhalational ✅• Provides rapid absorption; drug delivered directly to
lung tissue, where most of these drugs exert their action
o Other routes: Sublingual, buccal ✅• Absorbed more rapidly from oral mucosa,
leading to a more rapid onset; avoids breakdown of drug by stomach acids; avoids first-
pass metabolism
o Other routes: Rectal (Suppository) ✅• Relatively rapid absorption, good alternative
when oral route is not available; good for local or systemic drug delivery; usually leads
to mixed first-pass and non-first-pass metabolism
What does the protein-binding ability level of a drug mean? How do albumin levels
affect drug levels in the bloodstream? ✅o Lower albumin (protein) levels increase drug
levels in the bloodstream, because there are less proteins available to create bound,
drug-protein complexes (inactive drugs, too large to pass through capillary walls of
tissues)
4. Why is cytochrome P-450 so important? ✅o Microsomal enzymes; aid in
metabolism of medications; target lipid soluble (non-polar, lipophilic, fat-loving) drugs,
which are typically difficult to eliminate
What happens when grapefruit juice is taken with a drug that interacts with cytochrome
P-450? ✅
o Side effect: ✅: expected averse drug reaction
Undesirable = unexpected (i.e. allergic reaction: hypersensitivity response involving
immune system)
o Adverse reaction: ✅: any undesirable drug occurrence
Idiosyncratic reaction:
• Glucose-6-Phosphate Dehydrogenase Deficiency (G6PD): ✅): when exposed to
drugs such as sulfonamides, anti-malarials, and aspirin, patients may suffer life-
threatening hemolysis of RBCs; (13-20%) African-American, Kurdish Jewish (50%),
Sardinians (14%)
, adverse reaction: Drug-induced teratogenesis ✅: cause fetal structural defects;
BLACK BOX WARNING
adverse reaction: Mutagenic effects: ✅permanently changes genetic composition of
living cells
adverse reactions: drug-drug interactions ✅when two or more drugs come together
and either work together to create a synergistic, antagonistic, or additive effect
o Agonist: ✅drug binds to the receptor, there is a response
Ex: morphine stimulates opioid receptors
Partial Agonist: ✅drug binds to receptor, diminished response
o Antagonist: ✅drug binds to receptor; there is no response. Drug prevents binding of
agonist.
Ex: Narcan (naloxone) displaces morphine
Competitive antagonist: ✅compete with agonist for binding; if it binds, there is no effect
Non-competitive antagonist: ✅combine with different parts of receptor to inactivate it
o Synergists: ✅drug molecules work with other drug molecules
Produces greater effects than sum of individual drug actions
• 1+1 > 2
Can produce toxic effects
ETOH + tranquilizer = toxicity!
How are drugs metabolized? ✅o Metabolism = Biotransformation: drugs are
transformed into inactive metabolites, more soluble compound, more potent active
metabolite (ex: conversion of prodrug into active form), or less active metabolite
Primarily in liver; also in kidney, lungs, skin
Liver metabolizes drug from GI tract, reducing bioavailability (< 100%) in first-pass
effect; then, excretes unchanged drug to gallbladder
• Gallbladder bile + drug are reabsorbed into gut
What happens in liver dysfunction? ✅o Liver dysfunction causes jaundice: metabolic
rate affected
o Renal dysfunction (kidney failure): decreased drug metabolism and excretion
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