NURS 549 Pharm Midterm Exam With
Complete Solution
Pharmacokinetics - ANSWER What the body does to the drug once
administered
Pharmacodynamics - ANSWER The actions of a drug on the body
Absorption - ANSWER The transfer of the drug from the site of
administration to the bloodstream
Distribution - ANSWER The process by which the drug leaves the blood
stream and enters the interstitial and then tissue cells
Metabolism - ANSWER The drug is broken down to metabolites in the
tissues
Elimination - ANSWER Removal of drug from the body via bile, urine
Which drugs passively diffuse across membranes most easily: Un-ionized,
lipid-soluble drugs OR ionized, water-soluble drugs? - ANSWER Un-ionized,
lipid soluble drugs
What drugs are easily eliminated via the kidney? - ANSWER Ionized, water
soluble forms of drug
Where are weakly acidic drugs better absorbed? - ANSWER In the acidic
media of the stomach drug will remain protonated (un-ionized, lipid soluble)
Where will weakly basic drugs be better absorbed? - ANSWER In the basic
media of the small intestine the drug will remain protonated (un-ionized)
,Where is drug absorption most efficient? Stomach, SI or LI? - ANSWER The
small intestine, as it has the largest surface area and blood flow
First pass effect - ANSWER The initial metabolism in the liver of a drug
absorbed from the gastrointestinal tract before the drug reaches systemic
circulation through the bloodstream.
Oral bioavailability & relation to first pass effect - ANSWER The fraction of
an administered drug that reaches the systemic circulation after oral
administration. High first pass effect, low oral bioavailability
Bioavailability = (AUC oral / AUC injected) x 100
SubQ versus IM absorption - ANSWER SubQ tissue has less vascularity than
muscle tissue. IM absorption is faster
Rectal administration - ANSWER Avoids liver biotransformation. 50% of
drainage from rectal region bypasses portal circulation
Drugs that are unstable in the acidic environment of the stomach and have
0% bioavailability - ANSWER Insulin, Penicillin G
Bioequivalence - ANSWER Two drugs have comparable bioavailability
(similar time to peak blood concentration)
Pharmaceutical equivalence - ANSWER Drugs with the same active
ingredient, same dosage form, same route, identical in
strength/concentration
Therapeutic equivalence - ANSWER Pharmaceutical equivalents with the
same clinical effect and safety profile
,Drug distribution depends on... - ANSWER Cardiac output
Regional blood flow
Capillary permeability
Degree of drug binding to plasma and tissue proteins (drug that binds to
albumin may not distribute. rugs that bind tissue proteins may have
prolonged effect)
Volume of distribution (Vd) - ANSWER Hypothetical volume of fluid into
which the drug is disseminated - numeric value based on liters, patient
independent marker
Types of drugs with low Vd, higher Vd, and highest Vd - ANSWER Low Vd =
hydrophilic, large molecular weight, plasma protein-bound drugs that remain
in plasma compartment
Higher Vd = hydrophilic, low molecular weight, non-plasma bound drug,
distributes to plasma and interstitium
Highest Vd = Lipophilic, low molecular weight, non-plasma bound drug,
distributes to plasma, interstitium, and intracellular fluid
First order kinetics - ANSWER Non-linear, exponential elimination of drugs.
, A constant fraction of drug is metabolized per unit of time. Rate increases
concentration increases. Applies to vast majority of drugs
Zero order kinetics - ANSWER A constant amount of drug is eliminated per
unit time. Elimination is linear, independent and non-proportional to drug
concentration. All enzymes are saturated, at max capacity. Must manufacture
additional enzymes for future metabolism.
How must drugs be metabolized in order to be eliminated by the kidney? -
ANSWER Lipophilic drugs must be metabolized to more polar, hydrophilic
substances in the liver
Phase 1 metabolism - ANSWER Oxidation reactions by CYP450 enzymes,
reduction reactions, hydrolysis reactions
Phase 2 metabolism - ANSWER Conjugation reactions to make more
hydrophilic metabolites. Key for tylenol metabolism.
NEONATES - deficient in this conjugation system. Gray Baby Syndrome.
Steady state plasma concentration - ANSWER Point at which the amount of
drug administered = the amount of drug being eliminated. Plasma and tissue
levels remain constant.
Complete Solution
Pharmacokinetics - ANSWER What the body does to the drug once
administered
Pharmacodynamics - ANSWER The actions of a drug on the body
Absorption - ANSWER The transfer of the drug from the site of
administration to the bloodstream
Distribution - ANSWER The process by which the drug leaves the blood
stream and enters the interstitial and then tissue cells
Metabolism - ANSWER The drug is broken down to metabolites in the
tissues
Elimination - ANSWER Removal of drug from the body via bile, urine
Which drugs passively diffuse across membranes most easily: Un-ionized,
lipid-soluble drugs OR ionized, water-soluble drugs? - ANSWER Un-ionized,
lipid soluble drugs
What drugs are easily eliminated via the kidney? - ANSWER Ionized, water
soluble forms of drug
Where are weakly acidic drugs better absorbed? - ANSWER In the acidic
media of the stomach drug will remain protonated (un-ionized, lipid soluble)
Where will weakly basic drugs be better absorbed? - ANSWER In the basic
media of the small intestine the drug will remain protonated (un-ionized)
,Where is drug absorption most efficient? Stomach, SI or LI? - ANSWER The
small intestine, as it has the largest surface area and blood flow
First pass effect - ANSWER The initial metabolism in the liver of a drug
absorbed from the gastrointestinal tract before the drug reaches systemic
circulation through the bloodstream.
Oral bioavailability & relation to first pass effect - ANSWER The fraction of
an administered drug that reaches the systemic circulation after oral
administration. High first pass effect, low oral bioavailability
Bioavailability = (AUC oral / AUC injected) x 100
SubQ versus IM absorption - ANSWER SubQ tissue has less vascularity than
muscle tissue. IM absorption is faster
Rectal administration - ANSWER Avoids liver biotransformation. 50% of
drainage from rectal region bypasses portal circulation
Drugs that are unstable in the acidic environment of the stomach and have
0% bioavailability - ANSWER Insulin, Penicillin G
Bioequivalence - ANSWER Two drugs have comparable bioavailability
(similar time to peak blood concentration)
Pharmaceutical equivalence - ANSWER Drugs with the same active
ingredient, same dosage form, same route, identical in
strength/concentration
Therapeutic equivalence - ANSWER Pharmaceutical equivalents with the
same clinical effect and safety profile
,Drug distribution depends on... - ANSWER Cardiac output
Regional blood flow
Capillary permeability
Degree of drug binding to plasma and tissue proteins (drug that binds to
albumin may not distribute. rugs that bind tissue proteins may have
prolonged effect)
Volume of distribution (Vd) - ANSWER Hypothetical volume of fluid into
which the drug is disseminated - numeric value based on liters, patient
independent marker
Types of drugs with low Vd, higher Vd, and highest Vd - ANSWER Low Vd =
hydrophilic, large molecular weight, plasma protein-bound drugs that remain
in plasma compartment
Higher Vd = hydrophilic, low molecular weight, non-plasma bound drug,
distributes to plasma and interstitium
Highest Vd = Lipophilic, low molecular weight, non-plasma bound drug,
distributes to plasma, interstitium, and intracellular fluid
First order kinetics - ANSWER Non-linear, exponential elimination of drugs.
, A constant fraction of drug is metabolized per unit of time. Rate increases
concentration increases. Applies to vast majority of drugs
Zero order kinetics - ANSWER A constant amount of drug is eliminated per
unit time. Elimination is linear, independent and non-proportional to drug
concentration. All enzymes are saturated, at max capacity. Must manufacture
additional enzymes for future metabolism.
How must drugs be metabolized in order to be eliminated by the kidney? -
ANSWER Lipophilic drugs must be metabolized to more polar, hydrophilic
substances in the liver
Phase 1 metabolism - ANSWER Oxidation reactions by CYP450 enzymes,
reduction reactions, hydrolysis reactions
Phase 2 metabolism - ANSWER Conjugation reactions to make more
hydrophilic metabolites. Key for tylenol metabolism.
NEONATES - deficient in this conjugation system. Gray Baby Syndrome.
Steady state plasma concentration - ANSWER Point at which the amount of
drug administered = the amount of drug being eliminated. Plasma and tissue
levels remain constant.
