Pharmacology of Skin

Question 1

which drugs cause a urticarial drug reaction

Answer 1

beta-lactam antibiotics
aspirin
opiates
NSAIDs

Question 2

what response causes a urticarial drug reaction

Answer 2

IgE mediated response, type I hypersensitivity

Question 3

which drugs cause a pustular/bullous drug reaction

Answer 3

glucocorticoids
androgens
hypertensives

Question 4

glucocorticoids causes acneiform reactions true/false

Answer 4

true

Question 5

describe the appearance of fixed drug eruptions

Answer 5

well demarcated round/oval plaques

red and painful usually found on hands, lips and genitalia

Question 6

what types of drugs cause fixed drug eruptions

Answer 6

tetracyclines
paracetamol
NSAIDs
carbamazepine

Question 7

what two conditions can arise due to severe cutaneous adverse drug reactions and which is more severe

Answer 7

steven-johnson syndrome and toxic epidermal necrolysis - more severe

Question 8

how does toxic epidermal necrolysis present

Answer 8

flu-like symptoms with blistering, red rash around body causing skin to break down and expose to pathogens

Question 9

which drugs cause toxic epidermal necrolysis

Answer 9

sulfonamides, cephalosporins, carbamazepine and NSAIDs

Question 10

list some phototoxic drugs

Answer 10

fluoroquinolones, doxycycline 
thiazides 
quinine 
amiodarone 
porphrins

Question 11

what are the three routes a drug can be administered through the skin

Answer 11

topical - for local effects
transdermal
subcutaneous - for systemic effect

Question 12

what is the most important barrier for drug administration in the skin

Answer 12

stratum corneum

Question 13

in the brick and mortar structure what makes up the brick and mortar

Answer 13

bricks - corneocytes

mortar - hydrophobic layer of intercellular lipids

Question 14

the stratum corneum is hydrophilic or lipophilic

Answer 14

lipophilic

Question 15

drug penetration of the stratum corneum is transcellular or intercellular

Answer 15

intercellular - travels between the corneocytes

Question 16

what is a drug vehicle

Answer 16

a non-pharmacologically active substance that carries a drug

Question 17

give examples of drug vehicles

Answer 17

creams
ointments 
gels 
lotions 
pastes

Question 18

what two factors affect the absorption of a drug in the skin

Answer 18

movement of drug from stratum corneum

dissolved concentrations of drug in vehicle

Question 19

hydrophobic drug in hydrophobic base

Answer 19

soluble in both so partitions between the two

Question 20

hydrophobic drug in hydrophilic space

Answer 20

more soluble in the skin so will move towards it - best movement

Question 21

hydrophilic drug in hydrophobic space

Answer 21

low solubility in vehicle and skin so little movement

Question 22

hydrophilic drug in hydrophilic space

Answer 22

soluble in vehicle but not skin, does not move

Question 23

when are topical glucocorticoids used

Answer 23

treatment of eczema, psoriasis and pruritus

Question 24

what are the actions of glucocorticoids

Answer 24

anti-inflammatory
anti-proliferative
vasoconstrictive

Question 25

give an example of a mild steroid

Answer 25

hydrocortisone

Question 26

give an example of a moderate steroid

Answer 26

betnovate or eumovate

Question 27

give an example of a potent steroid

Answer 27

beclometasone dipropionate

Question 28

give an example of a very potent steroid

Answer 28

clobetasol propionate

Question 29

list some side effects of long term steroid use

Answer 29

``` thinning of the skin steroid rebound - less effective increased risk of infection - immunosuppression steroid rosacea stretch marks ```

Question 30

describe a cream and what lesions it can be used for

Answer 30

semi-solid emulsion of oil and water containing preservative used for moist, weeping lesions

Question 31

creams are non-greasy true/false

Answer 31

true

Question 32

describe an ointment and what lesions is can be used for

Answer 32

semi-solid mix of oil and soft paraffin | used for dry, scaly, lichenified lesions

Question 33

what is an advantage of an ointment

Answer 33

very good at restrictive transepidermal water loss

Question 34

what areas are lotions used for

Answer 34

dry hairy areas eg scalp

Question 35

describe a paste

Answer 35

finely powdered material, stiff and greasy so difficult to use

Question 36

what is the function of an emollient and which condition it is mainly used in

Answer 36

enhance hydration of epidermis | psoriasis

Question 37

when is a potassium permanganate bath used

Answer 37

treatment of exudative eczema and pompholyx

Question 38

give a list of antifungals and what conditions they are used to treat

Answer 38

clotrimazole and nystatin - candida infection | clotrimazole - ringworm infection

Question 39

give some examples of antipruitics

Answer 39

menthol, capsaicin, crotamiton

Question 40

what are keratolytics used for

Answer 40

soften kertain in viral warts and hyperkeratosis

Question 41

give an example of a keratolytic

Answer 41

salicylic acid

Question 42

what is the antibiotic of choice for rosacea

Answer 42

metronidazole

Question 43

psoriasis treatment is use of emollients plus 1 of which drugs

Answer 43

``` vitamin D analogue coal tar keratolytic glucocorticoid dithranol ```

Question 44

describe use of vitamin D analogue

Answer 44

clean, no smell but can cause irritation and can only use up to 100g a week for localised plaques only

Question 45

describe the use of coal tar

Answer 45

can be used anywhere in the body but very messy and smelly

Question 46

describe the use of dithranol

Answer 46

very effective with short term use on localised plaques but can cause irritation and staining even on normal skin