1
Q
The success of derm therapies is dependent on what factors?
A
- correct dx
- type of lesion being tx
- med being used
- vehicle
- method used to apply the med
2
Q
Whay may happen if the correct med is used but the wrong vehicle is used?
A
- respone to therapy may be delayed, inadequate or even worsened
- ex: using a glucocortiocid gel on hand eczema and fissures will cause increased pain and stinging due to alcohol base of gel
- ex: tx a moist lesion with an oitment may cause folliculitis secondary to its occlusive properties
3
Q
What is the vehicle (aka base)?
A
- substance in which the active ingredient is dispersed
- vehicle determines the rate at which the active ingredient is absorbed through the skin
- sterngth of topical is dependent on vehicle
- components of the base (may cause irritation or allergic response):
solvents
stabilizers
emollients
humectants
thickening agents
emulsifying agents
4
Q
Use of appropriate vehicle for specific types of lesions?
A
- both vehicle and active med need to be appropriate for the skin disease
- if it’s wet, dry it, and if its dry, wet it
5
Q
What would you use for acute contact dermatitis from poison ivy that has moist deep lesions?
A
- lotions will help dry up dermatitis
- will also provide cool, soothing relief
6
Q
What would you use for chronic psoriasis?
A
- this is a dry lesion - use creams or ointments to help retain native moisture, provide relief to dry, itching skin
7
Q
In general, what do you tx acute inflammation with? Chronic inflammation?
A
acute- tx with aqueous drying preparations
chronic- tx with greasier, lubricating compounds
8
Q
Topical drug penetration into the skin is determined by what?
A
- determined by the method of topical application
- site of application is also impt as variation in epidermal layer will alter the extent of drug absorption
9
Q
What is tachyphylaxis? soln to this?
A
- progressive decrease in clinical response due to repetitive application of a drug (glucocorticoids)
- occurs when body becomes tolerant to pharmacotherapeutic effects of a particular med
- soln: allow for drug free intervals, switch at various times to alternative agents
10
Q
Vehicles consist of what 3 basic ingredients?
A
- powder
- oils
- liquids
- combo of these 3 ingredients in varying proportions make up most commonly used vehicles
11
Q
Diff types of vehicles?
A
- powders
- solns
- tinctures
- lotions
- oils
- ointments
- creams
- gels
- aerosols and sprays
- shampoos
- foam
12
Q
When are powders used?
A
- aid in absorbing moisture, decrease friction and help cover wide areas easily
- primarily used in intertriginous areas to reduce moisture, maceration and friction
13
Q
What are solns?
A
- liquids with very minimal oil or solid content, but with active ingredients (ex - visine)
14
Q
What are tinctures?
A
- alcoholic or hydroalcoholic solns (may cause pain and irritation on erosions and abrasions)
15
Q
What are lotions? How potent? diff types?
A
- consist of suspension of powder in water
- considered LEAST potent topical therapies
- considered drying (even emollients)
- as lotions evaporate they cool and dry
- shake lotions - solids suspended within (calamine)
- emollient lotions: oil disperesed in water with surfactant (vaseline intensive care lotion)
- these are useful in hairy areas and conditions where large areas have to be tx
16
Q
What are creams- composition? Potency?
A
- semisolid emulsions of oil in water about equal proportion
- penetrates the stratum corneum of the skin well*
- cosmetically appealing
- can cause more adverse rxns b/c of preservatives
- Stronger than lotions but less potent than ointments
17
Q
What do ointments consist of? Potency?
A
- consist of water dropletes suspended in cont. phase of oil or of inert bases such as petrolatum (vaseline)
- most lubricating and moisturizing and thus desirable for dryer lesions
- facilitates heat retention, thery are semi-occlusive
- **greater penetration of meds than creams
- Most potent vehicle due to occlusive effect, but pt acceptance may be low b/c they are greasy
- useful for dry dermatoses in non-seborrheic, non-intertriginous areas
- not useful in hairy areas
18
Q
What do gels consist of? Useful in what?
A
- transparent semisolid emulsion that liquefies on contact with skin, drying as a thin, greaseless, non-occlusive film
- consist of hydrophillic base with water or acetone (avoid acetone on sensitive skin)
- combines the best therapeutic advantages of ointments with best cosmetic advantages of creams
- considered drying and are used in seborrheic areas (face, chest)
- used for exudative inflammation (poison ivy) and in scalp and hair bearing areas where other vehicles mat the hair
- useful for tx acne (Retin-A)
19
Q
Use of aerosols and sprays? Downside?
A
- sprays: alcohol based solns, pressurized and delivered as an aerosol
- considered to be drying
- wasteful: much of active med doesn’t reach the skin
- most frequently used in the scalp
20
Q
Use of foams? Downside?
A
- pressurized collections of gaseous bubbles in matrix of liquid film
- easy to spread and apply especially to scalp
- they are complex to make and can be more expensive
21
Q
Use of shampoos? Big educational point for pts?
A
- used primarily for seborrheic dermatitis of the scalp
- the active ingredient is mixed with shampoo
- educational pt: shampoo must usually be left on for 5-7 minutes after application for the med to be effective b/f being rinsed off
22
Q
What does strength of topical med depend on? Exceptions?
A
- dependent on vehicle
in general:
-ointment of topical corticosteroids are more potent than creams
-creams are usually more potent than lotions - exceptions - retin-A in gel form and solns are more effective and more irritating than cream form
23
Q
Most potent to least potent vehicles?
A
- oitment/gel - most potent
- cream - potent
- lotion - least potent
24
Q
What covers more body surface: cream or ointment?
A
- ointment will cover an area 5-10% larger
25
MOA of topical clucorticoids?
- pass through stratum corneum and cause vasoconstriction, decrease inflammation and inhibit cellular proliferation
- more potent the steroid the more vasoconstriction, less inflammation and less proliferation
- vasoconstriciton of normal skin can be quantified and serves as a parameter by which topical steroids are ranked in potency
26
Indications for topical glucocorticoids?
- TOC for most inflammatory conditions
- pruritic eruptions (dermatitis)
- hyperplastic disorders (psoriasis)
- infiltrative disorders (sarcoid)
* used on a rash when not fungal or viral
27
Pros to topical corticosteroid use?
- broad applicability in tx of numerous diseases
- rapid action with small dose
- ease of use: no odor or pain
- lack of sensitization
- prolonged stability
- compatible with most other topical meds
28
Adverse rxns of topical corticosteroids - suppression of hypothalamic pituitary system? Especially what drugs?
- paricularly class 1 agents
- adults applying a potent steroid in excess of 50-100 g wk (10-20 g in small kids) for more than 2 wks may cause suppression
- Clobetasol (strongest) known to cause suppression with only 2 grams
- risk is greatest with more potent steroids, with damage to stratum coneum or in thin skin such as kids
- except in infants, the mildest of steroids (hydrocortisone), is unlikely to result in systemic complications
29
local adverse rxns of topical corticosteroids?
- comon in any steroid use when used for longer than 2 wks
- burning, itching, or dryness are usually due to vehicle
- atrophy and telangiectasias are frequent in potent steroids or application to thin skin
- irreversible stretch marks: esp on legs, arms and abdomen
- skin fragility and easy brusing may occur in chronic use
- steroid rosacea (eruption of acne)
30
Dosage considerations of topical steroids?
- there is a marked regional variation in steroid penetration
- anatomic regions with a thin epidermis are significantly more permeable to topical steroid than thick skinned areas
31
Specific regional differences in percutaneous absorption?
- sole of foot: 0.14%
- palm: 0.83%
- forearm: 1%
- scalp: 3.5%
- forehead: 6%
- cheek: 13%
- genitalia: 42% (holy schnikes!)
32
What increases absorption of steroids?
- increased with increased skin hydration
- should be applied to moist skin after bathing to achieve optimal penetration and efficacy
- inflamed skin has increased penetration
- ointments allow for better percutaneous drug absorption (exception - betamethasone dipropionate (cream))
33
7 classes and 4 groups of topical steroids?
- super potent (class I)
- potent (class II-III)
- intermediate (class IV-V)
- mild (class VI-VII)
34
Selecting the right steroid?
- depends on condition
| - best to start with lowest potency agent needed and use it for short of a time as possible
35
When should super potent steroids be used?
- for severe dermatoses over non-facial/non-intertriginous areas
- useful over palms and soles
- ex:
psoriasis
severe atopic dermatitis
severe contact dermatitis
36
When are intermediate to potent strength steroids used?
- mild-moderate non-facial/non intertriginous dermatoses
37
When are mild to intermediate strength steroids be used?
- should be considered when large areas are tx b/c of likelihood of systemic absorption
38
When should mild strength steroids be used?
- for tx eyelid and genital dermatoses
39
SEs of mild strength steroids?
- rarely cause SEs, but intermittent therapy may be preferable to cont therapy for long term tx of large skin areas
40
SEs of potent to intermediate strength steroids?
- rarely cause SEs if used for less than 6-8 wks, except on face and intertriginous areas
41
SEs of super potent strength - Duration of use?
- shouldn't exceed 3 wks if possible
| - persistent lesions on small areas may be tx for longer time?
42
Tx duration dependent on location?
- facial, intertriginous, and genital dermatoses should be tx for short 1-2 wk intervals since these areas are most susceptible to atrophy, telangiectasia and acneiform eruption
- application to highly permeable areas also increases systemic absorption and is also why duration of tx should be limited to these areas
- topical steroid should be d/c when skin condition has resolved
- if cont. tx needed - pt should be monitored for development of adverse effects and/or tachyphylaxis
43
Use of topical steroids in kids?
- use low potency (class IV-VII)
- kids under 12 shouldnt use potent or super potent steroids
- exception fo severe dermatoses:
short courses of more potent (class I-III) for up to 2 wks
psoriasis, severe atopic dermatitis
- use for short durations and for appropriate inflammatory conditions
44
Should combo antifungal/glucocorticoids be used?
- No!!!
- usually a KOH scraping would diff 2 conditions
- these are super expensive compared to topical steroids and OTC antifungals
- steroid prep in combos are potent, increasing risk of cutaneous side effects
45
Topical antibacterials used in derm?
- Mupirocin (bactroban)
- neomycin
- gentamycin
- silver sulfazine
46
Benefits of topical antibacterials?
- tx a wide variet of potential pathogens
- no risk of ototoxicty or nephrotoxicity from aminoglycoside topicals
- drug concentration can be very high
- drugs are in more direct contact with organisms
- combos of various antibacterials are synergistic
- topical use helps to retard the emergence of resistant organisms
47
Bactroban (Mupirocin):
Effective against what bugs?
Used for?
- ointment and cream
- effective against most staph (even MRSA) and strep
- a few gram negative organisms are susceptible (E. coli, H flu, N. gonorrhea)
- **only topical antibacterial that may be used to tx impetigo due to staph aureus and or strep pyogens
- no contact desensitization
48
Neomycin:
| Effective against? Why don't derms use it?
- ointment or cream
- effective against:
gram (-) (except pseudomonas) and is 50x more active against staph than bacitracin
- most derms avoid neomycin b/c has greater incidence of allergic contact sensitivity than any other topical abx (this may be hidden b/c it frequently appears as though original cutaneous disease were unaffected by tx)
- So don't use it!
49
Use of gentamycin?
- ointment or cream
- greater activity against pseudomonas
- more active against staph and GABHS
50
Use of silvadene: silver sufadiazine? What does it cover against? CI in what pts? What may it cause in burn pts?
- 1% cream
- bacteriocidal against gram + (including staph aureus), gram negatives (pseudomonas) and candida albicans
- DON'T use in pts with sulfa allergies
- may cause leukopenia in burn pts with large surface area burns
- use: 2nd/3rd degree burns and chronic ulcers
51
MOA of polyene class of antifungals? What drugs are in this class?
- bind with sterols in fungal cell membrane - ergosterol
- this changes the temp of cell membrane from a more fluid to a more crystalline state
- the result is leakage of ions and small organic molecules leading to cell death
- animal cells contain cholesterol instead of ergosterol and so are much less susceptible to damage
- drugs:
Nystatin (mycostatin)
Amphotericin B (fungizone)
52
Use of Nystatin?
- ointment, cream
- used in tx of Candida infections of skin and mucous membranes
- oral preps are poorly absorbed from GI tract and will thus rid the oral and GI mucosa of candida but have no effect on systemic or cutaneous infections
53
Use of amphotericin B (fungizone)?
- 3% cream, lotion or ointment
- used topically to tx superficial Candida albicans
- ineffective against dermatophytes (ringworm) and tinea versicolor
- drug is yellow-orange and may stain clothes and skin
54
MOA of Allyamine class of antifungals? drugs?
- inhibit squaline epoxidase
- an enzyme necessary for ergosterol synthesis
- drugs:
terbinafine (lamisil)
Naftitine (Naftin)
55
Use of Terbinafine (lamisil)?
- OTC
- 1% cream
- used for dermatophytes (Tinea Pedis)
56
Use of Naftifine (Naftin)?
- Rx only
- 1% or 2% cream, gel, powder
- used in topical tx of tine corporis, cruris, and versicolor
57
MOA of Imadazole class? Drugs?
- inhibits the enzyme- lamosterol 14 alpha-demethylase
- enzyme necessary for converting lanosterol to ergosterol
- lack of ergosterol disrupts fungal membrane leading to inhibition of fungal growth
- Drugs:
clotrimazole (lotrimin, Desenex)
miconazole (Micatin, monostat)
ketoconazole (Nizoral)
58
Use of clotrimazole?
- lotrimin, mycelex: OTC
- cream, soln
- used to tx tinea corporis, tinea pedis, tinea cruris, tinea versicolor
59
Use of Miconazole?
- Monistat, Micatin: OTC
- 2% cream, lotion, vaginal supps
- same spectrum as clotrimazole
- used to tx vaginal infections due to candida albicans, also tx tinea pedis, tinea cruris, tinea corporis and tinea versicolor
60
Use of ketoconazole?
- Nizoral - Rx only
- 2% cream - ued in tx of tinea infections and tinea versicolor and candida
- 2% shampoo: used in tx of seborrheic dermatitis, there is an OTC shampoo that isn't Rx strength
61
Use of Econazole (Spectazole)?
- Rx only
- 1% cream
- same spectrum of activity as Clotrimazole
- used to tx tinea carpers, tinea pedis, tinea cruris, tinea versicolor
62
Application of Imidazole antifungals?
- once or twice daily application to affected area will generally result in clearing of superficial dermatophyte infections in 2-3 wks
- 3-4 applications to affected area will effectively tx intertriginous candidiases (use powder)
- topical won't clear up nail infection
- seborrheic dermatitis should be tx with 2x daily applications of ketoconazole until clinical clearing is obtained
63
what is MOA of ciclopirox Oxamine (Loprox)? Used for?
- broad spectrum hydroxypyridine anti fungal agent:
interes with cell membrane transport and fungal respiratory process
- 1% cream and lotion: used for dermatophytes, C. albicans and tinea versicolor
- 8% Penlac nail lacquer: mild to moderate onychomycosis of fingernails and toes
64
Use of Selenium sulfide (Selsun, Exsel)?
- OTC
- 1% and 2.5% solns
- used to tx seborrheic dermatitis, dandruff and tinea versicolor
- antimitotic agent, antibacterial and antifungal**
65
Use of Tolnaftate (Tinactin, Cruex)?
- OTC
- believed to inhibit squalene epoxidase
- 10% cream, powder, spray, ointment
- antifungal effective against tinea versicolor and all dermatophyte fungi
- ineffective against C. albicans
66
Acne preps that are used topically?
- azelic acid
- benzoyl preoxidase
- retinoids
- topical abx
- Dapsone
67
Use of Azelaic acid?
- naturally occuring in skin
- it is believed that azelaic acid clears acne by reducing pop. of P. acnes, decreasing the abnormal shedding of skin cells and reducing inflammation
- used to tx mild to moderate inflammatory and non-inflammatory acne
- also proven effective in tx dark spots that develop in some acne pts with skin of color
- well tolerated by most people and can be safely used for yrs
- side effects may include skin dryness and lightening of the skin where applied
68
Azelaic acid drug names?
- Azelex
- Finacea
- available in: gel (more drying, has alcohol base) and cream
69
Benzoyl peroxide use?
| Most common SEs?
- OTC
- benzoyl peroxide works by killing P. acnes
- it doesn't have anti-inflammatory abilities
- available in wide range of strengths and can be found as gel, lotion, cleanser, cream and wash:
many acne preps include benzoyl peroxide b/c research shows that benzoyl peroxide increases the effectiveness of some meds such as erythro and clindamycin
- when used in combo with abx - benzoyl peroxide reduces the likelihood of pt developing resistance to abx
- MC SEs: skin irritation, potential to bleach hair and fabrics as well as possible allergic rxn
70
Use of topical retinoids in acne tx?
| MC side effect?
* * mainstay of acne tx
- Rx to tx acne ranging from mild to moderately severe, topical retinoids are a derivative of Vit A and considered a cornerstone in acne tx
- primarily anti-inflammatory
- work to unclog pores and prevent white heads and black heads from forming
- **can irritate the skin and increase sun sensitivity so it is impt to use sun protection (even in winter)
- ad added benefit of these is that they may help diminish signs of aging, such as fine lines and wrinkles
71
Retinoic acid (Retin-A)?
- acid form of vitamin A
- action decreases cohesion b/t epidermal cells and increased epidermal cell turnover
- results in expulsion of open comedons and transformation of closed comedones to open ones
- promotes collagen synthesis, new blood vessel formation and thickening of epidermis
72
Use of Adapalene (differin)?
- mild retinoid
- 0.1% gel once daily
- less irritating than retin-A
- used for mild to moderate acne vulgaris
73
Use of Tazarotene (Tazorac)?
- retinoid
- 0.1% gel and cream
- used for mild to moderately severe facial acne and psoriasis
- use only in teens older than 12
- should be used by women of childbearing age only after contraceptive counseling
- preg: X
74
MC adverse effects of retinoids?
- Erythema and dryness: occurs in first few weeks of use, but can be expected to resolve with continued therapy
- minimize sun exposure and use protective sunscreen (some pts should d/c retinoid during summer if outside all the time)
75
General guidelines for using retinoids? Pt instruction?
- best to start with lowest strength and if too irritating on a daily basis go to every other or every 3rd day
- instruct pt to not put retinoid with benzoyl perixodase as BP oxidizes the retinoid (makes it ineffective)
- retinoid can be put on at night and a combo BP with topical abx in am
76
Use of topical clindamycin in acne tx?
- 1% soln or gel
- good activity against Propionibacterium acnes
- water based gel and lotion formulations are well tolerated and less likely to cause irritation
- allergic contact dermatitis is uncommon
- does come in a fixed dose with benzoyl peroxidase
77
Use of topical erythromycin in acne tx?
- first line topical abx
- used with benzyl peroxide to reduce resistance
- comes in variety of forms
- shouldn't be used as monotherapy as high bacterial resistance
78
Use of sodium sulfacetamide in acne tx? What pts need to avoid this med?
- used in tx of acne vulgaris and acne rosacea
10% lotion
10% wash
- DON'T use in pts with sulfa allergy
79
use of Dapsone 5% for acne? skin SE if applied with benzyl peroxide?
- MOA not well understood
- both anti-inflammatory and anti-bacterial
- applying dapsone w/ benzyl peroxide can turn skin orange
80
When is Permethrin cream used? Med of choice in what pop? Directions?
- OTC: lice and scabies
- med of choice: for children
directions:
-apply to entire body (if for scabies)
- leave on for 8-12 hrs
- kills mites and eliminates the risk of contagion w/in 24 hrs
- pruritus may continue for several days to 2 weeks after tx
- entire family should be tx
- all clothing and bedding washed
81
When is permethrin cream rinse used? What else is used?
- used to tx head lice and pubic lice
- has to be reapplied after 14 days for the most successful tx
- also use fine tooth comb to remove nits
82
Alt meds for lice and scabies?
- for older kids and adults: Lindane lotion
- Ivermectin (Stromectol): taken by mouth in 2 doses given a week apart also is effective and is especially helpful for severe infestations in people with weakened immune system
83
What are the topical immunossuppressives used?
- Tacrolimus (Protopic)
| - Pimecrolimus (Elidel)
84
Why are Topical Calcineurin inhibitors used? When are they used? MOA?
- nonsteroidal immunomodulating agents that do not have skin SEs that topical steroids do
- 2nd line tx for mild to moderate atopic dermatitis involving the face, including the eyelids, neck and skin folds
- MOA: inhibits effects of cytokine production but also may result in a decreased activity of T cells
- main adverse effects: mild stinging, burning, and pruritis
85
Use of Topical Calcineurin Inhibitors may increase the risk of what? What pops should these not be used in?
- May increase the risk of developing lymphomas and skin cancer b/c of MOA that leads to decreased activity of T cells
pops:
- they shouldn't be used on kids younger than 2YO
- they shouldn't be used for extended periods of time and over a minimum area
- they shouldn't be used for extended periods of time and over a minimum area
86
What are topical chemo (immuno-modifier) drugs used? and what are they used for?
- 5-FU
- Imiquimod
Used for:
- Skin cancer and actinic keratosis
87
MOA and use of 5-FU (Efudex)? Education for pt?
- MOA: intereferes with DNA synthesis, primarily in fastest growing cells
- used to tx actinic keratosis and low grade basal cell skin cancers
- use: apply to affected area using an applicator for 2-6 wks
- result: burning, peeling, blistering skin, more sun sensitized - need to protect (stay out of sun)
88
Imoquimod: MOA, use, and effects? When should this not be used?
- MOA: immune modifier: acts at several levels of immune system and promotes apoptosis in skin cancer cells
- tx for basal cell CA, actinic keratosis and genital warts
- Use: apply at noc either for 2 wks or longer only 2x a week then
- Effects: same as w/ 5-FU + systemic fatigue & flu like illness
- if a pt has another cancer they shouldn't use imoquimod: suppresses immune system
Dermatology
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