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Disease & Defense - Unit 3 > Dermatologic Therapeutics > Flashcards

Flashcards in Dermatologic Therapeutics Deck (23):
1

Drug factors affecting percutaneous absorption of topical medications

 Active drug concentration
 Composition of the vehicle
 Molecular size of the drug or prodrug
 Lipophilicity of the drug

2

Patient factors affecting percutaneous absorption of topical medications

 Presence of barrier disruption
 Anatomic location (including thickness of the stratum corneum)
 Skin hydration
 Occlusion

3

Types of vehicles for topical medications

 Ointments: Water in oil emulsion
 Creams: Oil in water emulsion
 Gels: Semisolid emulsion in alcohol base
 Lotions/Solutions: Powder in water (some oil in water)
 Foams: pressurized collections of gaseous bubbles in a matrix of
liquid film

4

Ointment characteristics and sites of use

-strong potency
-hydrating
-very low sensitization; low irritation risk
-good sites: non-intertriginous
-bad sites: face, hands, groin

5

Cream characteristics and sites of use

-moderate potency
-some hydration < ointments
-significant sensitization risk; low irritation risk
-good sites: most
-bad sites: areas w/maceration

6

Gel characteristics and sites of use

-strong potency
-drying
-significant sensitization; high irritation risk
-good sites: oral mucosa, scalp
-bad sites: areas w/fissures, erosions, or maceration

7

Lotions/solutions characteristics and sites of use

-low potency
-variably drying
-significant sensitization; moderate irritation risk
-good sites: scalp, intertriginous regions
-bad sites: areas w/fissures, erosions

8

Foams characteristics and sites of use

-stable at room temp but melts at body temp
-supersatured solution allows maximal delivery of active ingredients
-strong potency
-good sites: hair-bearing areas
-bad sites: areas w/fissures, erosions

9

Important factors in selecting appropriate vehicle

1. anatomic location
2. contact allergy/sensitization
3. irritancy

10

FTU definition

-amount dispensed from 5mm diameter nozzle that fits in the distal third of the index finger
-1 FTU=0.5g

11

FTUs required to cover face and neck

2.5 FTU

12

FTUs required to cover trunk (front or back)

7 FTU

13

FTUs required to cover arm

3 FTU

14

FTUs required to cover hand (both sides)

1 FTU

15

FTUs required to cover leg

6 FTU

16

FTUs required to cover foot

2 FTU

17

Mechanism of action of corticosteroids

-bind receptors in cytoplasm of cells --> ultimately alter transcription
-alter mRNA production of several inflammatory pathways:
-cAMP/CREB-binding protein
-nhibits nuclear factor-kb --> decreases cytokines, adhesion mlx, inflammatory enzymes
-interacts w/activating protein 1 (AP-1) which controls trxn of growth factor and cytokine genes

18

General classes of topical glucocorticosteroids

-Class 1(Superpotent)
-Class 2 (High potency)
-Class 3 (High potency)
-Class 4 (Medium potency)
-Class 5 (Medium potency)
-Class 6 (Low potency)
-Class 7 (Low potency)

19

Prototypical corticosteroids

-"gentle touch": Hydrocortisone 2.5% (cream or ointment)
-"almost all-purpose weapon": Triamcinolone Acetonide 0.1% (cream or ointment)
-"hercules": Clobetasol Propionate 0.5% (cream or ointment)

20

Hydrocortisone 2.5% characteristics

-class 7 (lowest potency)
-good for:
-mild eczema in children and adults
-inflammatory dermatoses @ face, intertriginous areas, groin

21

Triamcinolone Acetonide 0.1%

-class 4 (medium potency)
-good for:
-moderate spongiotic dermatoses (e.g. eczema, atopic dermatitis, allergic contact derm, athropod bites, drug reactions) @ trunk, extremities
-not on face, groin, intertriginous regions

22

Clobetasol Propionate 0.5%

-class 1 (superpotent)
-acute eruptions that need quick resolution (e.g. contact dermatitis or acute drug eruptions)
-not on face, groin, intertriginous regions

23

Adverse effects of topical glucocorticosteroids

-more potent = greater adverse effects
-skin atrophy = shiny, thin skin, telangiectasia, striae formation
-systemic side effects=adrenal suppression, Cushing's syndrome, growth retardation in children