Practice Questions & Verified Answers
Affinity - correct answers -The strength of attraction between a drug and its receptor, drugs with high
affinity are strongly attracted to their receptor, drugs with low affinity are weakly contracted. This
affinity is reflected in its potency, high affinity is very potent
Plateau or steady state - correct answers -When the amount of drug eliminated between doses equals
the dose administered, average drug levels will remain constant and plateau will have been reached.
Repeated doses of equal size cause the drug to increase in body until plateau or steady-state is
obtained; plateau is reached in 4 half lives
First-pass effect - correct answers -rapid inactivation of certain oral drugs by the liver; if the liver can
metabolize the drug quickly it is rendered inactive with no effect
therapeutic objective of drug therapy - correct answers -to provide maximum benefit with minimum
harm
drug absorption - correct answers -movement of a drug from its site of administration into the blood
Rate is influenced by chemical and physical properties and rate of dissolution, surface area, blood flow,
lipid solubility, and pH partitioning
drug distribution - correct answers -movement of drugs from blood to interstitial space in tissue and
onto the cells; determined by blood flow to tissues; ability to exit vascular systems, ability to enter cells;
blood flow determines rate of distribution
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, drug metabolism - correct answers -chemical or enzymatic alteration of drug structure
drug excretion - correct answers -Removal of drugs from the body via urine, saliva, sweat, saliva, breast
milk, expired air
kidney is most important organ for excretion
Loading dose - correct answers -for drugs with large half-lifes and when plateau must be achieved more
quickly a large initial dose may be administered
Maintenance doses - correct answers -when plateau is achieved and needs to be maintained with
smaller doses
Category A drugs - correct answers -Remote Risk of Fetal Harm:
Controlled studies in women have been done and have failed to demonstrate a risk of fetal harm during
the first trimester, and there is no evidence of risk in later trimesters
Category B drugs - correct answers -Slightly More Risk Than A: Animal studies show no fetal risk, but
controlled studies have not been done in women
or Animal studies do show a risk of fetal harm, but controlled studies in women have failed to
demonstrate a risk during the first trimester, and there is no evidence of risk in later trimesters.
Category C drugs - correct answers -Greater Risk Than B: Animal studies show a risk of fetal harm, but
no controlled studies have been done in women or
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