Pharmacology

Question 1

What are the 3 major routes of drug administration through the skin?

Answer 1

Topical, transdermal, subcutaneous

Question 2

Which route of drug administration is mainly used for local effect? Which are used for prolonged systemic effects?

Answer 2

Local = topical, Systemic = transdermal and subcutaneous

Question 3

What is the most important barrier to drug penetration?

Answer 3

Keratin layer

Question 4

What are adjacent corneocytes held together by?

Answer 4

Corneodesmosomes

Question 5

Both local and systemic drugs must cross the keratin layer. True or false?

Answer 5

True

Question 6

Penetration of the keratin layer normally only allow diffusion of which drugs?

Answer 6

Small, hydrophobic drugs

Question 7

The topical route is mainly used for treatment of what?

Answer 7

Superficial skin disorders

Question 8

What do keratolytic drugs do? When are they used?

Answer 8

Break down the keratin layer- used in warts

Question 9

What are 2 important factors which influence the rate and extent of absorption of a topically applied drug?

Answer 9

Solubility of the drug in the vehicle, movement of the drug from the vehicle to the keratin layer

Question 10

Transdermal drug delivery is driven by what?

Answer 10

Diffusion

Question 11

What type of drug dissolved in what type of vehicle will be the most effective at getting through the keratin layer?

Answer 11

Lipophilic drug in a lipophilic or hydrophobic vehicle

Question 12

Only the drug which is dissolved in the vehicle is able to be absorbed. True or false?

Answer 12

True

Question 13

Increased partitioning of a drug results from what?

Answer 13

Reduction in barrier function in the keratin layer

Question 14

What are the relative potencies of drugs in thick and thin skin?

Answer 14

Thick skin = high potency, thin skin = low potency

Question 15

What does it mean for a drug to have high potency?

Answer 15

Evokes a response at a low concentration

Question 16

Which is more potent, hydrocortisone butyrate or hydrocortisone acetate?

Answer 16

Hydrocortisone butyrate

Question 17

Corticosteroids have what effect on blood vessels?

Answer 17

Vasoconstriction

Question 18

Systemic side effects do not occur with topical administration of steroids. True or false?

Answer 18

False, it is less likely but systemic side effects can still occur

Question 19

Which is more potent, and ointment or a cream?

Answer 19

Ointment

Question 20

Describe subcutaneous administration?

Answer 20

A needle into adipose tissue below the skin surface

Question 21

A drug which is delivered via subcutaneous administration will reach the systemic circulation how?

Answer 21

By diffusion into capillaries or lymphatic vessels

Question 22

What are 3 advantages of using the skin as a site of administration?

Answer 22

Steady state concentration can be achieved, avoids first pass metabolism and absorption can be terminated rapidly

Question 23

Many drugs are suitable for transdermal administration. True or false?

Answer 23

False- not many drugs are suitable

Question 24

Glucocorticoids signal via what type of receptor? Specifically which one?

Answer 24

Intracellular receptors - specifically GRalpha

Question 25

Are glucocorticoids lipophilic or lipophobic? How do they enter cells?

Answer 25

Lipophilic- enter cells by diffusion through the plasma membrane

Question 26

What happens to glucocorticoids in the cytoplasm?

Answer 26

They combine with GRalpha and are translocated to the nucleus aided by importins

Question 27

What do glucocorticoids bind to in the nucleus?

Answer 27

Glucocorticoid response elements

Question 28

What happens once glucocorticoids have bound to GREs?

Answer 28

Transcription of specific genes is either switched on or off, mRNA levels are altered and mediator proteins are produced

Question 29

Name the bases which topical drugs can be used in?

Answer 29

Gels, creams, ointments, pastes, lotions

Question 30

What are creams? What do they contain?

Answer 30

Semisolid emulsion of oil in water. Contain emulsifier and preservatives.

Question 31

Do ointments contain preservatives?

Answer 31

No

Question 32

When should ointments be used?

Answer 32

If the skin is really dry or cracked

Question 33

What is a lotion?

Answer 33

A suspension of medication in water, alcohol or other liquid

Question 34

Where are lotions particularly useful?

Answer 34

To treat the scalp and hair bearing areas

Question 35

Where are gels used to treat?

Answer 35

Scalp, hair bearing areas and face

Question 36

What vehicle is often used in cooling and drying bandages?

Answer 36

Pastes

Question 37

What is the function of emollients and when are they used

Answer 37

Enhance rehydration of the skin, used in dry/scaly conditions especially eczema

Question 38

How much emollient should be prescribed weekly?

Answer 38

300-500g

Question 39

When and how should emollients be applied?

Answer 39

Directly after bathing, in the direction of hair growth

Question 40

What are some dermatological effects of topical steroids?

Answer 40

Steroid rosacea, fixed telangiectasia, perioral dermatitis

Question 41

What type of steroid should be started first?

Answer 41

Potent, and then reduced

Question 42

How much topical steroid is used for two hands? How much is used for the whole body?

Answer 42

Two hands = one fingertip length, whole body = 20-30g ointment

Question 43

What are tacrolimus and pimecrolimus examples of?

Answer 43

Calicneurin inhibitors

Question 44

What do calicneurin inhibitors do? When are they used?

Answer 44

Suppress lymphocyte activation, used in atopic eczema

Question 45

What can be added to calamine lotion for a cooling sensation?

Answer 45

Anti-pruritic e.g. menthol

Question 46

When are keratolytics used?

Answer 46

Viral warts, hyperkeratotic eczema, psoriasis, corns and calluses

Question 47

Use of vitamin D analogue in psoriasis is limited to what?

Answer 47

100g/week

Question 48

Psoriasis can be aggravated by what drug?

Answer 48

Beta blockers (propranolol)