Pharmacology L3

Question 1

Barriers to drug delivery

Answer 1

• molecular/ cellular permeation of external protective barriers of the body
• potential difficulties with efficient drug transportation and molecular targeting
• production of drug derivatives and/or swift elimination via biotransformation
• potential problems due to immune response

Question 2

Molecular/ cellular permeation of external protective barriers of the body

Answer 2

• anatomical barriers demarcate the interior system from its surrounding
• blood-tissue barriers (eg blood brain barrier)

Question 3

Potential difficulties with efficienct drug transportation and molecular targeting

Answer 3

• delivery via GI-tract: extremely acidic environment in stomach
• delivery via pharynx/ trachea/ bronchioli: mucociloary movement of trapped drug aerosols from pharynx to larynx
• limitations of plasma proteins transportation
• hydrophobic interactions (fatty tissue, membranes)

Question 4

What is biotransformation

Answer 4

Natural mechanisms that protects the body from ingested molecules

Question 5

Production of drug derivatives and/or swift elimination via biotransformation

Answer 5

• liver: major organ of drug biotransformation
• kidney: excretory function of drug or metabolite elimination

Question 6

Potential problems due to immune response

Answer 6

• natural protection against infectious agents; auto-immune complications
• potential allergic reactions, hypersensitivity, anaphylactic shock

Question 7

Drug administration is carried out by?

Answer 7

• enteral administration
• parental administration
• topical administration

Question 8

Enteral administration involves

Answer 8

• oral administration (swallowed or topically)
• buccal administration (between gums and cheek)
• sublingual administration (under the tongue)
• rectal administration

Question 9

How does oral administration occur

Answer 9

Via GI-tract to systemic circulation

Question 10

How does buccal administration occur

Answer 10

Through fast absorption via buccal mucosa

Question 11

How does sublingual administration occur

Answer 11

Fast absorption via sublingual mucosa

Question 12

How does rectal administration occur

Answer 12

Slow absorption through rectal mucosa

Question 13

Parenteral administration occurs through what?

Answer 13

Through injection or infusion (needle or catheter). Susceptible to high pH of stomach

Question 14

Types of parenteral administration

Answer 14

• intravenous
• intra- arterial
• intramuscular
• subcutaneous
• intra- articular
• intrathecal
• intradermal

Question 15

Intravenous

Answer 15

Achieves high drug concentration in circulatory system

Question 16

Intramuscular

Answer 16

Uniform drug absorption with rapid onset of drug action. If drug is to be given slowly at high conc eg opium overdose

Question 17

Subcutaneous

Answer 17

Slow drug absorption under the skin with prolonged drug action

Question 18

Intra-articular

Answer 18

Direct drug administration into inflamed joined cavities

Question 19

Intrathecal

Answer 19

Delivery into space between spinal cord and its protective sheath

Question 20

Intradermal

Answer 20

Drug administration within skin layers

Question 21

Topical administration (skin)

Answer 21

Administration to surface mucous membrane

Question 22

Oral administration

Answer 22

• tablets, capsules, solutions
• coated or matrix tablets so drug can get to the right place

Question 23

Inhalational administration

Answer 23

• aerosols, nebulizers

Question 24

Dermatological agents

Answer 24

• powders, (greasy) ointments, cream
• transdermal delivery systems

Question 25

Injection Or infusion

Answer 25

- intravenous - intra-arterial (rare) - subcutaneous - intramuscular - sublingual - rectal

Question 26

Drug absorption following oral administration occurs through

Answer 26

The gastrointestinal mucosal lining

Question 27

Absorption occurs through mucosal lining of?

Answer 27

The intestine

Question 28

Why does absorption occur through the intestine mucosal lining?

Answer 28

Due to slow processes involved in the disintegration of tablets and the dissolution of most drugs

Question 29

Where do solutions/ mixtures get absorbed

Answer 29

In the stomach region

Question 30

Mechanism of drug liberation

Answer 30

Disintegration (solid dose) Dissolution Absorption (liquid dose)

Question 31

What does modification of drug liberation mechanism do?

Answer 31

Protects sensitive agents and to alter time-course and site- specific absorption

Question 32

What do time-course and site-specific absorption do

Answer 32

Leads to retardation of drug release

Question 33

Oral dosage delivery forms

Answer 33

- drops -mixtures - effervescent solutions - matrix tablets - capsules - tablets - Coates tablets (with delayed release)

Question 34

What is the importance of different drug packages and methods of application

Answer 34

Difference drug packages deliver drugs to different targets Method of application affects drug release and absorption

Question 35

What do coated tablets have?

Answer 35

A drug-containing core and a covering shell to: - facilitate passing of drug on swallowing - mask a disagreeable taste - protect a perishable drug

Question 36

What do capsules have?

Answer 36

An oblong casing which contains drug in powder form

Question 37

What does a matrix tablet contain

Answer 37

The drug embedded in an inert meshwork which upon contact with water, is slowly released by diffusion

Question 38

What are inhalational drugs?

Answer 38

They involve drug delivery in the form of an aerosol by converting drug solution or micronized powder to gas form.

Question 39

How does drug delivery of inhalational drugs occur?

Answer 39

As a gas or mist by a nebulizer or spray dispenser. Delivery is mostly to bronchial mucosa

Question 40

Effectiveness of delivery process of inhalational drugs depends on

Answer 40

- size of aerosol particles - position of inhaler device - coordination between spray release and inspiration

Question 41

Depth of drug penetration of particles >100micro(m)

Answer 41

Trapped in oropharyngeal cavity

Question 42

Depth of drug penetration of particles: 0-60micro(m)

Answer 42

Trachea (bronchi)

Question 43

Depth of drug penetration of particles <2micro(m)

Answer 43

Bronchioli(alveoli). Very little, mostly exhaled

Question 44

Rank the methods of drug application using injection/infusion from fastest to slowest

Answer 44

1. Intravenous injection 2. Intramuscular injection 3. Subcutaneous injection 4. Oral application: slowest, biggest chance of being derivatized

Question 45

Factors that play a role in the delay of pain killer action

Answer 45

- large amounts of undigested food in GI-tract may slow down passage of some pharmacological agents - dissolved agents usually act faster than substances in stomach acid-resistant capsules - drug- drug interactions can have major effects on the pharmacological effects of pain killers

Question 46

What is bioavailability

Answer 46

Bioavailability refers to the extent and rate at which the drug enters systemic circulation, thereby accessing the site of action.

Question 47

Bioavailability of an active substance depends on?

Answer 47

- patient specifics - drug preparation

Question 48

Bioavailability of Aspirin

Answer 48

Fast-acting, water-soluble, already absorption in the stomach, with lower levels of bioavailability

Question 49

Bioavailability of Paracetamol

Answer 49

Slower-acting, but higher levels of bioavailability after approximately an hour

Question 50

Bioavailability of Ibuprofen

Answer 50

Fast acting and high bioavailability, but may be negatively affected by large amounts of i digested food in GI-tract