NURS 5220 Pharmacology NA General Principles | 2025 -2026 LATEST UPDATED |
COMPREHENSIVE QUESTIONS WITH 100% RATED ANSWERS
What is the Cytochrome P-450 System? Hepatic microsomal enzymes that metabolize drugs,
primarily in the liver
Where are Cytochrome P-450 enzymes found? In the smooth hepatic endoplasmic
reticulum, with some extrahepatic sites
How are Cytochrome P-450 enzymes named? First number denotes genetic family, next
letter describes genetic subfamily, second number stands for specific gene or isozyme
What is genetic variability in hepatic enzyme activity? Variations in enzyme activity among
individuals due to genetic differences
What can genetic variations in hepatic enzyme activity lead to? Changes in drug metabolism,
which can cause toxicity or decreased drug efficacy
What are inhibitors and inducers of hepatic enzymes? Substances that can either inhibit or
enhance hepatic enzyme activity
What are Monoamine Oxidases (MAO)? Enzymes that catalyze the oxidation of monoamines
,Where are MAOs found? Bound to the outer membrane of mitochondria
How many isoenzymes of MAO are there? 2: MAO-A and MAO-B
What is the role of MAO-A? Sole catecholamine metabolic enzyme in sympathetic neurons
What is the role of MAOs in catecholamine degradation? They are responsible for the first
step of degradation in other tissues, further processed by COMT
What are MAO Inhibitors? A major class of drugs that inhibit the activity of MAOs
What happens during reduction? There is a gain of electrons
What is hydrolysis? Addition of water to break ester or amide bonds and form smaller
molecules
What are esterases? Enzymes that split ester bonds, found in red blood cells and plasma
What are Phase 2 reactions? Conjugation reactions where a drug or metabolite is
conjugated with an endogenous substrate.
, What are the types of Phase 2 reactions? Glucuronidation, acetylation, and sulfation
reactions.
What is the significance of slow acetylators? They may have prolonged or toxic responses to
normal doses of drugs due to decreased rates of metabolism.
What is the predominant enzyme type in Phase 2 reactions? Transferases.
What is the result of Phase 2 reactions? More polar compounds that are more highly ionized
at physiologic pH, increasing water solubility of the drug.
What is the general characteristic of metabolites from Phase 2 reactions? Metabolites
almost always have little or no biologic activity.
How are metabolites from Phase 2 reactions excreted? Renally excreted.
What is the Hoffman degradation? A series of spontaneous chemical degradation steps that
break down quaternary amines into a tertiary amine and an alkene.
Is the Hoffman degradation enzyme, organ, and age independent? Yes.
What factors affect the Hoffman degradation? pH and temperature.
COMPREHENSIVE QUESTIONS WITH 100% RATED ANSWERS
What is the Cytochrome P-450 System? Hepatic microsomal enzymes that metabolize drugs,
primarily in the liver
Where are Cytochrome P-450 enzymes found? In the smooth hepatic endoplasmic
reticulum, with some extrahepatic sites
How are Cytochrome P-450 enzymes named? First number denotes genetic family, next
letter describes genetic subfamily, second number stands for specific gene or isozyme
What is genetic variability in hepatic enzyme activity? Variations in enzyme activity among
individuals due to genetic differences
What can genetic variations in hepatic enzyme activity lead to? Changes in drug metabolism,
which can cause toxicity or decreased drug efficacy
What are inhibitors and inducers of hepatic enzymes? Substances that can either inhibit or
enhance hepatic enzyme activity
What are Monoamine Oxidases (MAO)? Enzymes that catalyze the oxidation of monoamines
,Where are MAOs found? Bound to the outer membrane of mitochondria
How many isoenzymes of MAO are there? 2: MAO-A and MAO-B
What is the role of MAO-A? Sole catecholamine metabolic enzyme in sympathetic neurons
What is the role of MAOs in catecholamine degradation? They are responsible for the first
step of degradation in other tissues, further processed by COMT
What are MAO Inhibitors? A major class of drugs that inhibit the activity of MAOs
What happens during reduction? There is a gain of electrons
What is hydrolysis? Addition of water to break ester or amide bonds and form smaller
molecules
What are esterases? Enzymes that split ester bonds, found in red blood cells and plasma
What are Phase 2 reactions? Conjugation reactions where a drug or metabolite is
conjugated with an endogenous substrate.
, What are the types of Phase 2 reactions? Glucuronidation, acetylation, and sulfation
reactions.
What is the significance of slow acetylators? They may have prolonged or toxic responses to
normal doses of drugs due to decreased rates of metabolism.
What is the predominant enzyme type in Phase 2 reactions? Transferases.
What is the result of Phase 2 reactions? More polar compounds that are more highly ionized
at physiologic pH, increasing water solubility of the drug.
What is the general characteristic of metabolites from Phase 2 reactions? Metabolites
almost always have little or no biologic activity.
How are metabolites from Phase 2 reactions excreted? Renally excreted.
What is the Hoffman degradation? A series of spontaneous chemical degradation steps that
break down quaternary amines into a tertiary amine and an alkene.
Is the Hoffman degradation enzyme, organ, and age independent? Yes.
What factors affect the Hoffman degradation? pH and temperature.
