Elimination

Question 1

Renal excretion involves (3 things)

Answer 1

Glomerular filtration, passive tubular secretion, active tubular secretion

Question 2

Renal clearance is inversely correlated with:

Answer 2

age and creatinine clearance

Question 3

The distribution of phase of elimination or the ___ phase is:

Answer 3

redistribution of a drug from the plasma and vessel rich group to the less perfused tissues in the peripheral compartment
On a graph-rapid downstroke after IV bolus

Question 4

The elimination phase or ___ phase:

Answer 4

is after distribution slows, gets slow continuous elimination from the central compartment
On a graph-slow downstroke after distribution

Question 5

Half life/time is:

Answer 5

time it takes for 50% of the drug to be cleared from the body

Question 6

After how many half-lives is a drug considered cleared from the body?

Answer 6

5

Question 7

Context sensitive half-time:

Answer 7

The time is takes for 50% of a drug to be cleared from the plasma after stopping a drug infusion.

Question 8

What is zero order kinetics?

Answer 8

When the plasma concentration of drug exceeds capacity of metabolizing enzymes. Results in a constant amount of drug metabolized per unit time. ex: alcohol, aspirin, phenytoin

Question 9

Zero order kinetics makes a (linear or sloped) graph?

Answer 9

linear

Question 10

Half life ____ as concentration _____

Answer 10

decreases, decreases

Question 11

What is first order kinetics?

Answer 11

A constant fraction or % of available drug is metabolized in a given time period. It’s dependent on the plasma concentration. 50% of the drug metabolized every 2 hours. Doesn’t matter if it’s 100mcg or 500mc.g

Question 12

First order kinetics makes a (linear/sloped) graph?

Answer 12

sloped

Question 13

C max is:

Answer 13

Highest concentration in the blood

Question 14

C min is:

Answer 14

Lowest concentration in the blood

Question 15

Clearance is:

Answer 15

volume of plasma cleared of a drug by renal excretion and/or liver metabolism by unit of time. Can be influenced by drug properties and body’s capacity to eliminate it

Question 16

What is steady state?

Answer 16

The point when drug elimination is equal to the rate at which the drug is made available.

Question 17

Hepatic metabolic capacity, response of 0=, response of 1=

Answer 17

0=no metabolism, 1=maximal metabolism (Vm)

Question 18

Clearance is dependent on:

Answer 18

`blood flow (Q) and extraction ratio (ER). Clearance=QxER

Question 19

Extraction ratio is:

Answer 19

the fraction of a drug coming in to the liver that is extracted

Question 20

Perfusion Dependent Elimination:

Answer 20

depends more on blood flow to liver, minimal influence from enzymes. ER >0.7

Question 21

Capacity Dependent Elimination:

Answer 21

depends more on liver enzymes, less on blood flow. ER<0.3

Question 22

Glomerular Filtration depends on amount of drug bound to ____ and ______.

Answer 22

plasma proteins and molecular weight.

Question 23

Passive tubular secretion is affected by:

Answer 23

pH, rate of tubular flow

Question 24

Creatinine clearance equation

Answer 24

(140-age) x weight (kg)/72 x SCr all (x 0.85 if female)

Question 25

Age differences that affect clearance: Elderly 1. ____GFR, ____blood flow, ___fat (increased Vd)2.Neonate: Immature ____ ____, poor ___function in the 1st year of life.

Answer 25

decreased, decreased, increased,

liver enzymes, renal