Pharm exam 1

Question 1

What permeates plasma membrane?

Answer 1

Small, non-ionized, lipophilic drugs

Question 2

What type of drug can be filtered at the kidney glomerulus?

Answer 2

Free, Unbound drug

Question 3

Agonist

Answer 3

Drug that activates its receptor upon binding

Question 4

Antagonist

Answer 4

Drugs that bind to a receptor without eliciting a response

Question 5

Bioavailability

Answer 5

the fraction of drug absorbed into the systemic circulation after extravascular administration.

IV drugs have a bioavailability of 100%

Question 6

Clearance

Answer 6

Ratio of the rate of elimination of a drug to its concentration in plasma

Question 7

Efficacy

Answer 7

The maximum response that can be achieved with a drug. Greater the Emax graeter the efficacy of drug

Question 8

First order kinetics

Answer 8

occurs when a constant proportion of the drug is eliminated per unit time. Rate of elimination is proportional to the amount of drug in the body. The higher the concentration, the greater the amount of drug eliminated per unit time. In = out.

Constant PROPORTION of drug is eliminated per time

Question 9

First pass metabolism

Answer 9

Refers to hepatic inactivation of certain oral drugs.

Phenomenon of drug metabolism whereby the concentration of a drug is greatly reduced before it reaches the systemic circulation.

Question 10

Potency

Answer 10

The drug concentration (EC50) required to produce 50% of the drugs maximal effect. Thus the lower the EC50 of a drug, the greater S potency.

Question 11

Prodrug

Answer 11

Agent that must undergo chemical or enzymatic transformation to the active drug so that the metabolic product can exhibit the desired pharmacological response (e.g., nucleoside reverse transcriptase inhibitor, conversion of prazepam to desmethyldiazepam)

Question 12

Steady state concentration

Answer 12

situation where the overall intake of a drug is fairly in dynamic equilibrium with its elimination. In practice, it is generally considered that steady state is reached when a time of 4 to 5 times the half-life for a drug after regular dosing is started.

Question 13

Therapeutic index

Answer 13

One good indicator of how much wiggle room you have between a therapeutic dose and a lethal dose is the measurement of therapeutic index. The larger the therapeutic index the safer the drug

Question 14

Zero order kinetics

Answer 14

a constant amount of drug is eliminated per unit time. The rate of elimination is constant and is independent of the total drug concentration in the plasma

Question 15

1 compartment model of drug distribution and elimination

Answer 15

Drug enters the body (“compartment 1”) and drug leaves the body; all body tissue and fluids are considered part of this one compartment; assumes rapid distribution of a drug to tissues. Drugs that don’t distribute extensively into extravascular space are well described by the one-compartment model (for example, aminoglycosides, which are polar and distributed primarily to extracellular water).

Question 16

2 compartment model of drug distribution and elimination

Answer 16

Drug enters the body (“compartment 1”) and then leaves the central compartment to either (1) enter a peripheral compartment (compartment 2) OR (2) leaves the body; drug that is in the peripheral compartment can re-enter the central compartment (recirculate). An example is digoxin, where following IV administration, plasma levels of the drug rise (compartment 1), and then decrease as the drug is distributed into muscle tissue (compartment 2) until an equilibrium is reached.

Question 17

Excretion requires drug to be

Answer 17

polar, ionized, water soluble

Question 18

biotransformation I and II will make drug more or less polar?

Answer 18

More

Question 19

Weak acids are excreted faster in ______ urine and weak bases are excreted faster in _______ urine.

Answer 19

alkaline, acidic