NUR-641E Mid-Term Exam Study Guide
Understand what a prodrug is, and activation/inactivation by liver
enzymes, and how it differs from active drugs.
The liver is the principal site of drug metabolism. Although metabolism typically
inactivates drugs, some drug metabolites are pharmacologically active—sometimes
even more so than the parent compound. An inactive or weakly active substance
that has an active metabolite is called a prodrug, especially if designed to deliver
the active moiety more effectively.
Know what Bioavailability (BA)
a term used in pharmacology and nutritional and environmental sciences.
In pharmacology, it refers to the degree and rate at which an administered
drug is absorbed by the body's circulatory system, the systemic circulation.
Bioavailability is an essential measurement tool since it determines the
correct dosage for non-intravenous administration of a drug availability
means
Bioavailability. In pharmacology, bioavailability (BA or F ) is a
subcategory of absorption and is the fraction of an administered dose of
unchanged drug that reaches the systemic circulation
Bioavailability is affected by chemical instability, solubility and first-
pass metabolism
The first pass effect- is a phenomenon of drug metabolism whereby the
concentration of a drug is greatly reduced before it reaches the systemic
circulation. It is the fraction of drug lost during the process of absorption
which is generally related to the liver and gut wall.
Bioequivalence does not affect bioavailability
Bioequivalence is the similarity of two drugs that share the same desired
outcome for patients. Pharmaceutical equivalence means two drugs release
, the active ingredient into the bloodstream at the same amount and same
rate. When assessing how well a generic drug works, scientists evaluate its
bioequivalence to the name-brand version.
Understand what the Cytochrome P450 system is in the liver
Cytochrome P450 enzymes are primarily found in liver cells but are also
located in cells throughout the body. ... Cytochrome P450 enzymes
account for 70 percent to 80 percent of enzymes involved in drug
metabolism. Cytochrome P450 enzymes also function to metabolize
potentially toxic compounds, including drugs and products of endogenous
metabolism such as bilirubin, principally in the liver.
Clopidogrel (Plavix) is a prodrug and must be activated by hepatic CYP2C19
metabolism; individuals who are poor metabolizers may not form the active
metabolite and have reduced antiplatelet response.
A drug’s half-life determines how often the drug is administered?
The elimination half-life of a drug is a pharmacokinetic parameter that
is defined as the time it takes for the concentration of the drug in the
plasma or the total amount in the body to be reduced by 50%. In other
words, after one half-life, the concentration of the drug in the body
will be half of the starting dose.
Steady state of a drug is reached in approximately 5 to 6 times the half-life
Inhalation, oral and parenteral drug action and onset of effects?
Inhalational administration can be used. The lungs serve as an effective
route of administration of drugs. The pulmonary alveoli represent a large
surface and a minimal barrier to diffusion. The lungs also receive the total
cardiac output as blood flow. Thus, absorption from the lungs can be very
rapid and complete.
Bioavailability of drugs administered orally varies greatly.
Understand what a prodrug is, and activation/inactivation by liver
enzymes, and how it differs from active drugs.
The liver is the principal site of drug metabolism. Although metabolism typically
inactivates drugs, some drug metabolites are pharmacologically active—sometimes
even more so than the parent compound. An inactive or weakly active substance
that has an active metabolite is called a prodrug, especially if designed to deliver
the active moiety more effectively.
Know what Bioavailability (BA)
a term used in pharmacology and nutritional and environmental sciences.
In pharmacology, it refers to the degree and rate at which an administered
drug is absorbed by the body's circulatory system, the systemic circulation.
Bioavailability is an essential measurement tool since it determines the
correct dosage for non-intravenous administration of a drug availability
means
Bioavailability. In pharmacology, bioavailability (BA or F ) is a
subcategory of absorption and is the fraction of an administered dose of
unchanged drug that reaches the systemic circulation
Bioavailability is affected by chemical instability, solubility and first-
pass metabolism
The first pass effect- is a phenomenon of drug metabolism whereby the
concentration of a drug is greatly reduced before it reaches the systemic
circulation. It is the fraction of drug lost during the process of absorption
which is generally related to the liver and gut wall.
Bioequivalence does not affect bioavailability
Bioequivalence is the similarity of two drugs that share the same desired
outcome for patients. Pharmaceutical equivalence means two drugs release
, the active ingredient into the bloodstream at the same amount and same
rate. When assessing how well a generic drug works, scientists evaluate its
bioequivalence to the name-brand version.
Understand what the Cytochrome P450 system is in the liver
Cytochrome P450 enzymes are primarily found in liver cells but are also
located in cells throughout the body. ... Cytochrome P450 enzymes
account for 70 percent to 80 percent of enzymes involved in drug
metabolism. Cytochrome P450 enzymes also function to metabolize
potentially toxic compounds, including drugs and products of endogenous
metabolism such as bilirubin, principally in the liver.
Clopidogrel (Plavix) is a prodrug and must be activated by hepatic CYP2C19
metabolism; individuals who are poor metabolizers may not form the active
metabolite and have reduced antiplatelet response.
A drug’s half-life determines how often the drug is administered?
The elimination half-life of a drug is a pharmacokinetic parameter that
is defined as the time it takes for the concentration of the drug in the
plasma or the total amount in the body to be reduced by 50%. In other
words, after one half-life, the concentration of the drug in the body
will be half of the starting dose.
Steady state of a drug is reached in approximately 5 to 6 times the half-life
Inhalation, oral and parenteral drug action and onset of effects?
Inhalational administration can be used. The lungs serve as an effective
route of administration of drugs. The pulmonary alveoli represent a large
surface and a minimal barrier to diffusion. The lungs also receive the total
cardiac output as blood flow. Thus, absorption from the lungs can be very
rapid and complete.
Bioavailability of drugs administered orally varies greatly.
