Derm Therapies: Principles and Dosage Forms Flashcards
1
Q
What must be taken into account when determining an appropriate patient-specific approach?
A
- safety
- practicality
- expense
2
Q
Vehicle
A
substance in which the active ingredient is carried
3
Q
What are the characteristics of an ideal vehicle?
A
- easy to apply
- non allergenic
- nontoxic
- nonirritating
- non dehydrating
- non-greasy
- chemically stable and non-reactive
- cosmetically appearing
- bacteriostatic
4
Q
Ointment
A
- inert base such as petrolatum
- most are water-in-oil emulsions
5
Q
Application of Ointments
A
- clean and dry qday
- thin layer
- rub completely into skin
6
Q
Benefits of Ointments
A
- retains moisture
- lubricates
7
Q
Disadvantages of Ointments
A
- not on acutely inflamed lesions or intertriginous areas
- promotes bacterial growth
- cosmetically unpleasant
8
Q
Use and Example of Ointment
A
- for dermatitis
- hydrocortisone ointment
9
Q
Cream
A
oil in water
10
Q
Application of Cream
A
- clean and dry qday
- thin layer
- rub completely into skin
11
Q
Benefits of Cream
A
- non occlusive
- cosmetically appealing
12
Q
Disadvantages of Cream
A
- harder to apply than lotions or gels
- messy
- most people use too much
13
Q
Use and Example of Cream
A
- tinea corporis
- clotrimazole cream
14
Q
Gel
A
- semi solid emulsion of oil in water
- contains propylene glycol
15
Q
Application of Gel
A
- usually bid
- rub into skin
16
Q
Benefits of Gel
A
- quick drying
- clear
- non-staining
- best for hairy areas, face
- non oily
17
Q
Disadvantages of Gel
A
drying
18
Q
Use and Example of Gel
A
- acne
- benzoyl peroxide
19
Q
Lotion
A
- suspension or solution of powder in water base
- often with alcohol or astringents
20
Q
Application of Lotions
A
- apply tid or qid
- remove qd
- 6 ounces should cover one adult
21
Q
Benefits of Lotion
A
- cooling effect
- non-occlusive
- can be used over large area
- drying
22
Q
Disadvantages of Lotions
A
- avoid hairy areas
- avoid on weeping sores or oozing areas
- not useful for dry skin
23
Q
Uses and Examples of Lotions
A
- acne, benzoyl peroxide lotion
- scabies, lindane lotion
24
Q
Solution
A
medication in water, alcohol or propylene glycol
25
Application of Solutions
usually qday or bid
26
Benefits of Solutions
- cooling effect
- dry weeping lesions
- vasoconstriction
- good for hairy areas, moist folds
27
Disadvantages of Solutions
- avoid use on dry skin (drying)
| - may cause temporary burning sensation
28
Use and Example of Solution
- seborrheic dermatitis
| - lidex solution
29
Powder Application
best applied with cotton ball or shaker
30
Benefits of Powder
- absorbs moisture
- cooling and drying
- decreases friction, irritation
- discourages bacterial growth
- intertriginous areas
31
Disadvantages of Powder
- inhalation
| - caking
32
Use and Example
tinea pedis, miconazole powder
33
Paste
powder incorporated into ointment or cream
34
Benefit of Paste
protective barrier
35
Use and Example of Paste
diaper dermatitis, zinc oxide
36
Mechanism of Action for Topical Corticosteroids
-they inhibit phospholipase A, which is at the very beginning of the inflammatory reaction
(then can't get aracadonic acid --> prostaglandins, leukotrienes, etc)
37
Indications for Topical Corticosteroids
- all inflammatory pruritic eruptions (eg dermatitis, eczema)
- hyperplastic disorders (eg psoriasis)
- infiltrative disorders (eg sarcoid, granuloma annulare)
38
Contraindications for Topical Corticosteroids
- any viral, fungal or tubercular skin lesions
| - herpes simplex
39
Potential Adverse Effects for Topical Corticosteroids
- atrophy
- striae (stretch marks)
- contact dermatitis
40
Low Potency Topical Corticosteroids
- class VII
- modest anti inflammatory properties
- OTC products
- larger surface areas
41
High Potency Topical Corticosteroids
- class I
- easily absorbed systemically
- limit exposure to < 2 weeks
- small surface area
- do not use occlusive dressing
42
How to Use Topical Corticosteroids
- application frequency bid-tid
- rub into skin completely
- use appropriate strength then change to lower potency after acute disease controlled
- covering large areas may cause systemic toxicity
- taper gradually to reduce rebound flare
43
How to Choose the Topical Corticosteroid
- LOW potency for: kids, mild conditions, thin skin (eg face)
- HIGH potency for: severe inflammation and thicker skin (palms and soles)
- formulation influences potency: ointments > creams > lotions
44
Quantity (think fingertip unit)
- fingertip unit: amount of cream from tube of 5 mm diameter nozzle that can be squeezed from fingertip to first joint
- this is about 0.5 g and can cover one adult hand
