# Phar 631 Exam 1 (Lecture 3&4)

1) Entire dose of drug is input at once into bloodstream
2) Drug distributes instantaneously through all tissues (dissolved in single compartment of uniform fluid where drug is eliminated)
3) Drug eliminates from body/ elimination occurs immediately after

One compartment open model after IV bolus injection

The drug amount in the body is not determined directly but the plasma drug concentration can be determined. They are related by what?

Volume of distribution

Logarithms have what units?

They have NO units

If plasma drug concentration-time profile is not linear on a semi-log plot after an IV bolus dose, the drug may be _

unevenly distributed in different regions in which some tissues are slowly penetrated ( two compartment model)

The fraction of dose remaining depends only on what?

the number of half life after dosing

Time when the plasma drug concentration remains within the therapeutic range, above the minimum effective level

Duration of action

One compartment open model assumes changes in the plasma levels of a drug will result in _?

proportional changes in tissue drug levels

Distribution of drugs to various tissue organs occur depending on

blood flow to tissue, lipophilicity of drug, molecular weight of drug, binding affinity of the drug for the tissues

The apparent volume of distribution can also be calculated from knowledge of the _ and _ and _?

Dose, elimination rate constant, and area under the curve

Calculating the apparent volume of distribution using dose, elimination rate constant, and AUC is _?

Model- independent method

For each drug, the apparent volume of distribution is _?

Constant

The elimination rate constant is proportional to what?

The rate at which the drug concentration in the body declines over time

For first order, the elimination rate constant _?

Does not change over time

For first order process, clearance is _?

constant, regardless of the drug concentration

If non compartment model analysis is not desirable, a non compartment method may be used to calculate clearance from _and _?

Dose and AUC

The most accurate kinetic method to determine the volume of distribution and the distribution kinetics of a drug in a patient is to give the drug _?

Single IV bolus dose