Flashcards in Session 1 Deck (15):

1

## How do you calculate steady state concentration in plasma?

### CpSS = dose rate / clearance

2

## How do you calculate loading dose?

### Volume of distribution x CpSS

3

## What is the difference between zero order and first order kinetics?

###
Zero (non-linear) = rate of elimination is constant. No half-life can be defined.

1st (linear) = rate of elimination is proportional to drug level. Constant fraction of drug is eliminated in unit time. Elimination becomes non-linear at higher levels.

4

## What is clearance?

### The volume of plasma that is completely cleared of the drug per unit time.

5

## How do you calculate half life?

### T1/2 = (0.693 x Vd)/clearance

6

## Name CYP inhibitors

###
G- grapefruit juice

O- omeprazole

D- disulfiram

E- erythromycin

V- valproate

I- isoniazid

C- cimetidine/ciprofloxacin

E- ethanol

S- sulphonamides

7

## Name CYP inducers

###
P- phenytoin

C- carbamezepine

B- barbiturates

R- rifampicin

A- alcohol

S- sulphonylureas

8

## Describe phase 1 and phase 2 of drug metabolism

###
1 = oxidation/reduction/hydrolysis via CYP 450

2 = conjugation with glucoronyls/sulphates/methyls/acetyles etc.

9

## How do you calculate volume of distribution?

### Total amount of drug in the body / plasma concentration of drug at time zero

10

## What are the major fluid compartments of the body?

###
Plasma, extracellular and intracellular fluid.

11

## What factors affect drug distribution?

###
Lipophilicity (moves from blood plasma to tissues)

Hydrophobicity

Plasma binding reduces entry into tissues.

Amount of tissue and density of binding sites within that tissue.

12

## How do you calculate bioavailability?

### Amount of drug reaching systemic circulation / total amount of drug given

13

## How do you calculate oral bioavailability?

### The amount getting in orally / Total amount administered via IV.

14

## What are parenterally delivered drugs?

### Do not involve the GI tract. E.g. IV, subcutaneous, transdermal, intramuscular and intrathecal.

15