Bioavailabilty

Question 1

What is bioavailability

Answer 1

The sufficient amount of concentration a drug must reach to work

Question 2

What is absolute bioavailability

Answer 2

It measures how much the drug reaches the bloodstream when taken orally vs IV

Question 3

What factors affect bioavailability

Answer 3

• pharmaceutical factors
• physiological factors
  -route of administration

Question 4

Define pharmaceutical factors

Answer 4

Physical properties of the drug

Question 5

What are examples of pharmaceutical factors

Answer 5

Particle size, crystalline structure, salt form

Question 6

What manufacturing variables affect bioavailability

Answer 6

-pharmaceutical ingredients
-special coatings (aspirin)
-nature and types of dosage form
- Dissolution and disintegration time

Question 7

What patient related factors affect bioavailability

Answer 7

1. physiological factors
2. Interaction with food

Question 8

Examples of physiological factors

Answer 8

-Ph of GI fluids
- gastric emptying rate
- intestinal motility
-age/sex
-first pass metabolism

Question 9

What interactions affect bioavailability

Answer 9

-food
-fluid volume
-other drugs

Question 10

What routes of administration affect bioavailability

Answer 10

IV
IM
SC
ORAL
TRANSDERMAL
RECTAL

Question 11

What is the bioavailability level of IV

Answer 11

100%

Question 12

What is the bioavailability level of IM

Answer 12

75-100%

Question 13

What is the bioavailability level of Oral medication

Answer 13

5-100%

Question 14

What is the bioavailability level of rectal

Answer 14

30-100%

Question 15

What is the bioavailability level of transdermal

Answer 15

80-100%

Question 16

Why are ora drug less bioavailable

Answer 16

• active component doesn’t reach systemic circulation

Question 17

What cause the active component not reaching the systemic cupirculation

Answer 17

-being destroyed in stomach/ intestines
-drug not being absorbed into GI tract due to it being removed by first pass metabolism

Question 18

How does soulubilty affect bioavailability

Answer 18

Low soluble = low bioavailability

Question 19

What is an excipient

Answer 19

Inactive component in drugs (may increase shelf life)

Question 20

What do excipients do in relation to bioavailability

Answer 20

It affects dissolution and disintegration

Question 21

What are the effects of food on bioavailability

Answer 21

Food may increase or decrease bioavailability

Question 22

What medications bioavailability is reduce by food

Answer 22

Penicillin,erythromycin,thyroxine

Question 23

When should medication bioavailability decreased by food be taken

Answer 23

30 minutes before

Question 24

Why should some medications be take with food

Answer 24

They cause gastric symptoms when taken on an empty stomach

Question 25

Absorption on what medications is delayed by food

Answer 25

Aspirin,paracetamol,dioxin and frusamide

Question 26

Why would there be in increase of bioavailability in the presence of food

Answer 26

-When drug is highly soluble in fat
-When there is a delay in gastric emptying
- first pass metabolism is reduced

Question 27

What happens if there’s a delay in gastric emptying

Answer 27

Time increase for poorly soluble drugs