dose relationship

Question 1

What is a graded dose?

Answer 1

Response relationships depict the effect of varying doses of a drug on an individual

Question 2

What is a normal distribution?

Answer 2

A “normal” distribution is also known as a bell-shaped curve or Gaussian curve. In a Gaussian or normal distribution, the mean , mode and median would all have the same (or similar) value and would look like the figure. Example would be body height, heart rate, blood pressure ect in a population.

Question 3

What distribution does a drug response in a population usually show? why?

Answer 3

normal. because of individual variability, the response to a drug is not uniform in different subjects.

Question 4

What is a quantal dose-response curve?

Answer 4

shows the average dose-releated effects of a drug in population of individuals. examples: survived vs non survived, sleep vs no sleep

Question 5

What is therapeutic index?

Answer 5

it shows how selective the drug is in producing its therapeutic effects versus its adverse effects

Question 6

What does a larger therapeutic index mean?

Answer 6

means greater margin of safety of a drug. Drugs with a small TI require frequent monitoring.

Question 7

how to find Certain safety factor

Answer 7

LD1/ED99

Question 8

what is the therapeutic window?

Answer 8

the range of drug concentration that provides therapeutic effects but with minimal toxic effects.

Question 9

Advantages of Enteral route

Answer 9

Simple, inexpensive, convient, painless no infection

Question 10

Disadvantages of Enteral route

Answer 10

Requires GI absorption. Slow delivery to site of pharmacologic action

Question 11

Advantages of parenteral route

Answer 11

Rapid delivery to site of pharmacologic action. High bioavailability

Question 12

Disadvantages of parental route

Answer 12

irreversible, infection, pain, fear, skilled personnel required.

Question 13

Advantages of mucous membrane route

Answer 13

-rapid delivery to site of pharmacologic action, -often painless, -simple, -convenient , -low infection, -direct delivery to affected tissues possible

Question 14

Disadvantages of mucous membrane route

Answer 14

few drugs have chemical characteristics or formulations that allow them to be administered via this route

Question 15

Advantages of transdermal route

Answer 15

-simple -convenient -painless -excellent for continuous or prolonged administration

Question 16

disadvantages of transdermal route

Answer 16

-requires highly lipophilic drug -slow delivery to the site of pharmacologic action -may be irritating

Question 17

What is the absorption pattern of IV route

Answer 17

-rapid onset -suitable for large volumes and for complex mixtures when diluted

Question 18

What is the special utility of IV route?

Answer 18

-valuable for emergency use -permits dosage titration and controlled drug delivery -usually required for protein and peptide drugs

Question 19

What are the limitation and precautions of IV route?

Answer 19

-increased risk of adverse effects -must inject slowly as a rule -not suitable for oily solution or poorly soluble substances

Question 20

What is the absorption pattern for Subcutaneous route?

Answer 20

slow onset

Question 21

What is special utility for subcutaneous route?

Answer 21

may be used for some poorly soluble suspensions, or slow-releasing implants

Question 22

What are the limitations and precautions for subcutaneous route?

Answer 22

-Small volumes -possible pain or necrosis from irritating chemicals

Question 23

What is the absorption pattern of IM route?

Answer 23

immediate onset

Question 24

What is the special utility of IM route?

Answer 24

suitable foe moderate volumes including oil based drugs

Question 25

what are the limitations or precautions for IM route?

Answer 25

-Can affect lab test (eg creatine kinase) -IM hemorrhage -painful

Question 26

What is the absorption pattern for PO route?

Answer 26

variable, depends on many factors

Question 27

What is the special utility for PO route?

Answer 27

-most convenient and economical -usually safer

Question 28

What are some of the limitation and precautions for PO route?

Answer 28

-requires patient compliance -bioavailability potentially erratic and incomplete

Question 29

What is the distribution phase after giving an IV?

Answer 29

immediately after IV administration of a drug, it rapidly distributes from “blood” (the vascular compartment) to “extravascular volume” in other body parts. The plasma concentration shows a steep decline.

Question 30

What is the elimination phase after giving an IV?

Answer 30

when the drug concentration decreases slowly following its metabolism and excretion

Question 31

What is the first pass effect?

Answer 31

Following intestinal absorption, the portal blood delivers the drug to the liver, which is responsible for most of the biotransformation (metabolism) before drugs entering the systemic circulation

Question 32

What route does the first pass effect impact?

Answer 32

only orally administered drugs

Question 33

What may happen to some drugs by the first pass effect?

Answer 33

Some drugs may be extensively metabolized and inactivated by the liver, whereas other drugs may be converted into active compounds

Question 34

What does the fraction of administered drug that reaches the systemic circulation depend on?

Answer 34

-route of administration -drugs chemical form -Patient variabilities (enzymes, and transporter proteins in GI track and liver)

Question 35

How to you find bioavailability?

Answer 35

F=(quantity of drug reaching systemic circulation)/ (quantity of drug administered)

Question 36

what is the rising phase?

Answer 36

drug continues to be absorbed and distributed until the drug concentration (Cp) reaches a peak. Drug effects intensify.

Question 37

What is the decaying phase?

Answer 37

drug elimination becomes more dominant. effect disappears when Cp falls below drugs therapeutic level