Pharmacokinetics

Question 1

What is a drug?

Answer 1

A substance used for treatment, relief, diagnosis or prophylaxis of a disease

Question 2

What are the 3 sources where drugs can come from?

Answer 2

Plant
Animal
Mineral

Question 3

How do enteral drugs enter the body?

Answer 3

Anything involving digestive tract. Mouth to rectum

Question 4

Where do parenteral drugs go?

Answer 4

Avoids the gut so any route other than via gastrointestinal tract

Question 5

Give examples of parenteral drugs? ( not through digestive tract )

Answer 5

Transdermal - patches
Implantation
Intramuscular - muscle
Intrathecal - spine ( epidural )

Question 6

What does TOP TIPS stand for?

Answer 6

Tropical, oral, parenteral, transdermal, inhalation & subcutaneous ( under the skin )

Question 7

What is a subcutaneous drug?

Answer 7

Applied under the skin

Question 8

What is the pharmacokinetic phase?

Answer 8

ADME

Absorption
Distribution
Metabolism
Excretion

Question 9

Absorption across cell membranes involves what transports?

Answer 9

Passive - no energy required. Movement from a high to low concentration

Active - energy is required. Drugs move against the concentration gradient

Question 10

Factors that may affect the absorption of drugs across the GI tract?

Answer 10

Drug preparation - how quickly it disintegrates

Interaction - pH of stomach contents, food and other drugs

Physiological factors - how quickly the drug is moved through the digestive tract

Question 11

How does blood flow to a tissue affect distribution?

Answer 11

Drugs will reach higher concentrations in tissues which have a good blood supply eg, Brain. However, reduced flow to tissues and organs will affect distributions eg, blood brain barrier

Question 12

Some substances blocked from entering the brain tissue?

Answer 12

Toxins, some drugs and specific bacteria

Question 13

What is the first pass effect?

Answer 13

The effect liver metabolism has upon the drug during its first passage through the liver and in particular how much of the drug is inactivated

Question 14

If taken orally, where is the tablet absorbed across??

Answer 14

The wall of the stomach and / or the small intestine

Question 15

What is biotransformation?

Answer 15

The conversion of molecules from one form to another within an organism, often associated with change in pharmacological activity

Question 16

What are the main organs involved in elimination of drugs?

Answer 16

But, Skin, Lungs, Salivary grands, sweat glands, breast milk and Kidneys

Question 17

What is bioavailability?

Answer 17

Describes the fraction of administers dose of the drug that reaches the systemic circulation

Question 18

How much bioavailability of a drug is there when it’s administer intravenously ( vein )?

Answer 18

100%

Question 19

Why does propranolol have a bioavailability of 25%?

Answer 19

Because 75/85% is metabolised via 1st oasis effect ( metabolised by liver ) if taken orally before it can reach the circulation

Question 20

Why is morphine usually given via intramuscular injection?

Answer 20

Takes longer for plasma concentration to reach and it lasts longer

Question 21

What does onset mean?

Answer 21

Time from administration to when the therapeutic effect occurs

Question 22

What is a modified release?

Answer 22

Designed to slowly release drug into the gastrointestinal tract over a period of time

Question 23

What is a therapeutic range?

Answer 23

Optimum plasma level in which it has its therapeutic effect

Question 24

What is a therapeutic window for a drug?

Answer 24

Describes the levels in plasma which a drug can act

Question 25

What organs are most likely to be affected by drug toxicity?

Answer 25

Liver and kidneys

Question 26

Name a withdrawal symptom that can be experience when stopping opioids ( heroin and morphine ) after a long period of time?

Answer 26

Headaches

Question 27

Pharmacokinetics is?

Answer 27

How the body handles the drug

Question 28

Tolerance is?

Answer 28

A decrease in pharmacological effect when a drug is given repeatedly

Question 29

Modified release predations are designed to?

Answer 29

Slowly release drug over a period of time

Question 30

What happens to the drug in the liver?

Answer 30

Metabolic processes will convert the drug into a more water-soluble compound by increasing its polarity

Question 31

Name a drug sourced by a plant origin?

Answer 31

Digoxin