60: Topical Agents

Question 1

dead keratinocytes

Answer 1

stratum corneum

Question 2

living layers of epiermis

Answer 2

basal layer

spinous layer and granular layer

Question 3

cells of ______ layer synthesize most epidermal prtns

Answer 3

spinous

Question 4

cell renewal and mitotic activity occurs in ______ layer

Answer 4

stratum basale

Question 5

rate-limiting step for percutaneous absorption

Answer 5

passage through stratum corneum

Question 6

3 absorption pathways of intact skin?

which is most common route?

Answer 6

1. shunt route through appendages
2. transcellular route through corneocytes of stratum corneum (hydrophilic drugs)
3. through intercellular domains ** most common for small uncharged molecules

Question 7

water in oil emulsion =
oil in water emulsion =
water-soluble emulsion =
powder in water =
fine solid or liquid particles dispersed in gas =
semisolid with finely powdered material =
alcoholic solutions =

Answer 7

ointments
creams
gels/foams
lotionos/solutions
aerosols
pastes
tinctures

vehicle choice affects the rate and extent of absorption of drug

Question 8

what should be used in scalp and hairy areas? intertriginous areas?

Answer 8

lotions, gels, solution, foams, and aerosols

creams, lotiions, and solutions

Question 9

skin is dry and scaly so add …

wet and oozing add…

Answer 9

ointment

tinctures

if it is wet, dry it and if it is dry, wet it

Question 10

What influences the rate of percutaneous absorption?

Answer 10

• concentration of drug in vehicle
• partition coefficient (ability of drug to leave vehicle and move into outer layers of stratum)
• drug diffusion coefficient (decreasing MW of drug elevates diffusion)
• thickness of stratum corneum

Question 11

most topicallly effective drugs are at least somewhat…

Answer 11

lipophilic

Question 12

how do the following things affect PCA?

• inflamed skin
• hydrated skin
• occlusion of medication
• age of patient decreased

Answer 12

• increase PCA
• increase PCA
• increase PCA
• increase PCA (% topical applied to smaller body SA)

Question 13

Pathogenesis of Acne

Answer 13

microcomedone (hyperkeratotic, sebum secretion increased) –> comedone –> inflammatory papule/pustule –> nodule

Question 14

MOA erythromycin and clindamycin

Answer 14

inhibit prtn synthesis

antibiotics

Question 15

antibiotic MOA metronidazole

Answer 15

interacting and disrupting DNA

Question 16

MOA sodium sulfacetamide

Answer 16

kills p. acnes by inhibiting folic acid biosynthesis

Question 17

acne MOA azelaic acid

Answer 17

reduce inflammation and reduces keratinization

reduces growth of bacteria such as p. acnes and staph. epidermidis

Question 18

side effects azelaic acid

Answer 18

skin lightening and skin dryness

Question 19

MOA benzoyl peroxide

Answer 19

anaerobic antibac by releasing oxygen

antiinflammatory by inhibiting activity of
neutrophils

also keratinolytic

Question 20

which antibiotic has no resistance with long term use?

Answer 20

benzoyl peroxide

Question 21

MOA salicylic acid

Answer 21

increases solubilization of stratum corneum by altering keratin by breaking hydrogen bonds

clears comedones by desquamation

Question 22

MOA tretinoin

Answer 22

decreases adhesiveness of follicular epithelial cells responsible for producing microcomedones

increases mitotic activity in follicular cells which caufses extrusion of comedones

reduces keratinization

Question 23

benzoyl peroxide and _____ whould not be applied simultaneoulsy

Answer 23

Tretinoin

benzoyl peroxide inactivates tretinoin

Question 24

MOA adapalene

Answer 24

reduces cellular proliferation and inflammation - comedolytic

Question 25

oral retinoid used to treat severe acne

Answer 25

Isotretinoin

Question 26

MOA isotretinoin **

Answer 26

suppresses sebum production by inducing apoptosis in sebum producing cells of the sebaceous glands

Question 27

adverse effects isotretinoin

Answer 27

teratogenesis

+/- 1 mo contraceptive with treatment

Question 28

MOA tazarotene

Answer 28

decreases inflammation and epidermal hyperproliferation

Question 29

adverse effects tazarotene

Answer 29

teratogenic — preggers class X

Question 30

drugs to treat acne that inhibit sebaceous gland function

Answer 30

antiandrogens
oral contraceptives
isotretinoin

Question 31

pathogenesis of psoriasis

Answer 31

autoimmune disease

inflamamtion and keratinocyte hyperproliferation

Question 32

woman given oral Acitretin for severe psoriasis and now wants to get preggers. What do you tell her?

Answer 32

highly teratogenic with prolonged elimination time

women should avoid pregnancy for 3 yr after being administered acitretin

Question 33

MOA calcipotriene

Answer 33

vit D analog that inhibits proliferation of keratinocytes and reduces inflammation

slight risk hypercalcemia and hypercalciuria

Question 34

coticosteroids weak - intermediate - high

Answer 34

hydrocortiosne
mometasone furoate
clobetasol propionate

Question 35

MOA corticosteroids to treat psoriasis

Answer 35

reduce inflammation and inhibit immune function disorders

antiproliferative qualities as well

Question 36

tachyphylaxis =

Answer 36

diminished therapeutic effect

can occur with corticosteroids when high potency class are applied daily for 2 wks

prevent with alternate day applicaitons

Question 37

topical and systemic side effects to corticosteroids

Answer 37

topical : atrophy, acne, fungal infection, retarded wound healing, contact dermatitis, glaucoma, cataracts

systemic: hypothalamus pit adrenal axis suppression, cushings syndrome, growth retardation

Question 38

chronic inflammatory skin disorder associated with intense pruritus and dried flaking skin =

Answer 38

eczema aka atopic dermatitis

treat with corticosteroids

secondary infection a risk (tx with antibiotics)

Question 39

uses of photochemical therapy

Answer 39

alopecia
cutaneous t cell lymphoma
eczema
psoriasis

Question 40

MOA methoxsalen and trioxsalen

Answer 40

unknown - they are psoralens administered topically or orally then exposed to UV light