Topical Pharm Flashcards
The success of dermatologic therapies is dependent upon what main factor?
the vehicle!! (the base in which the active medication is delivered)
The vehicle determines ___ and ____.
Types of bases/vehicles?
vehicle determines the rate of absorption AND strength of the topical.
Types:
-solvents, stabilizers, emollients, humectants, thickening, emulsifying agents.
“if its wet, ___ it. If its dry, ____ it.”
Acute inflammation is treated with drying or moistening agents? Chronic inflammation?
If its wet, dry it. If its dry, wet it.
Acute inflammation is treated with aqueous drying preparations and chronic inflamm is treated with greasier, lubricating cmpds.
What determines drug penetration?
What is tachyphylaxis? How do we fix this?
method of topical applications
site of application
Tachyphlaxis: “tolerance,” a progressive decrease in clinical response to repetitive application of a drug.
Fix: allow for drug free intervals, switch at various times to alternative agents.
Vehicles consist of what three basic ingredients?
Powder, oils, liquid.
*combos of these ingredients in varying proportios make up the most commonly used vehicles.
Describe the function of the following:
- powders
- solutions
- tinctures
- lotions
powders: aid in absorbing moisture, decrease friction
Solutions: lotions w/ minimal oil or solid content. (visine)
Tinctures: alcoholic or hydroalcoholic solutions (may cause pain and irritation on erosions and abrasions.) drying agent
Lotions: powder in water. drying, may be shake(solids suspended within), emollients (oils disperes in water)
*useful in hairy areas and conditions where large areas have to be treated.
Describe the function of the following
- creams
- Ointments
- gels
- aerosols
- shampoo
creams: semisolod emulsions of oil and water, penetrate stratum corneum well
Ointment: water droplets suspended in oil. MOST lubricating and moisturizing**
- heat retention
- greatest potency
- not useful in hairy or intertriginous areas.
Gels: semisolid emulsion that liquifies on contact with skin, drying***
- used in seborrheic areas
- useful in poison ivy and acne (Retin-A)
aerosols: drying
shampoo: use primarily for seborrheic dermatitis 7 minutes
List the following in order from most potent to least;
- cream
- lotion
- ointment
Most: ointment
*most potent d/t occlusive effects
Cream
Least: lotion
Topical Glucocorticoids:
- MOA
- Indications
- adverse rxns
- what factors causes increased absorption of these?
MOA: pass through stratum corneum and cause vasoconstriction, decrease inflamm, and inhibit cellular proliferation
Indications:
- inflamm conditions
- pruritic eruptions
- hyperplastic disorders (psoriasis)
- infiltrative disorders (sarcoid)
Adverse Rxns:
- suppression of hypothalamic-pituitary system (excess of 50-100g weekly for greater than 2wks)
- burning, itching, dryness
- atrophy
- telangiectasias
- irreversible stretch marks
- skin fragility and easy bruising
- steroid rosacea
absorption factors:
-areas with thin epidermis are more permeable to topical steroids than thick-skinned areas.
-Be sure to use a not very potent steroid and be very sparing when applying steroids to face and genitalia. (dont use for more than 2wks)
- absorption is increased with increased skin hydration
- inflamed skin has increased penetration
How do you choose a steroid?
When do you use super potent class one topical steroid?
start with lowest potency agent needed and use for as short of period of time as possible.
Class 1 super potent: severe dermatoses over non-facial/non-intertriginous areas.
ex. palms/soles, psoriasis, severe atopic dermatitis
* should not exceed three weeks tx and on SMALL areas.
when do you use each of the following strengths of steroids?
- intermediate-potent
- mild to intermediate
- mild
intermed-potent: mild-mod non-facial/non-intertriginous dermatoses
*use less than 6-8wks
mild-intermediate: large areas b/c of the likelihood of systemic absorption
Mild: treating eyelid and genital dermatoses
How do you know how much topical steroid to dispense?
Can children use topical steroids?
take into consideration;
- surface area
- potency
- duration of tx
- vehicle (powder,gel, aersol, cream, ointment, etc)
yes, but need to use low potency (class IV to VII). if under 12yo they should not use potent or super potent topical steroids. if under 8yo you should let peds or derm doc rx.
Antifungal/glucocorticoids:
-do we use these?
NOOOOO!!!!! if you do, youre lazy!!! : /
What are the topical antibacterials?
mupirocin (bactroban)
Neomycin
Gentamycin
Silver Sulfazine
Bactroban (Mupirocin) :
- effective against which bug?
- indications
Effective against most staph and strep, few gram negatives (e. coli, N. gonorrhea, H. flu)
Indication: ONLY topical antibacterial used to treat impetigo d/t staph aureus or strep pyogenes
Neomycin:
- effective against which bugs?
- is this used often? Why
effective against gram - bugs and is 50x more active against staphylococci than bacitracin.
No, we avoid this because it is responsible for a greater incidence of allergic contact sensitivity than other topical abx.
Gentamycin:
-effective against which bugs?
pseudomonas, staph, and GABS
Silvadene
- aka
- effective against which bugs?
- dont use in which pts?
- use
aka: silver sulfadiazine
effective against gram + such as staph aureus and gram - pseudomonas, and candida albicans.
dont use in pts with sulfa allergy!!
use: 2nd/3rd degree burns and chronic ulcers.
What are the topical antifungal classes? Which drugs are in each class?
polyene :
- nystatin (mycostatin)
- amphotericin B (Fungizone)
allymaine:
- Terbinafine (lamisil)
- Naftifine (naftin)
Imadazole:
- clotrimazole (lotrimin, desenex)
- miconazole (micatin, monostat)
- Ketoconazole (nizoral)
- econazole (spectazole)
Other:
- ciclopirox oxamine (Loprox)
- selenium sulfide (Selsun)
- tolnaftate (Tinactin)
Polyene class:
-MOA
Nystatin:
-used for what types of infections?
Amphotericin B
-used for what types of infections?
Polyene class: bind with sterols(ergosterol) in the fungal cell membrane
Nystatin:
- used to tx candida infections of the skin and mucous membranes.
- have no effect on systemic or cutaneous infections when taken orally.
Amphotericin B:
- used topically to treat superficial candida albicans.
- ineffective against dermatophytes and tinea versicolor.
Allyamine class:
-MOA
Terbinafine:
-used for what types of infections?
Naftifine:
-used for what types of infections?
inhibits squaline epoxidase (an enzyme necessary for ergosterol synthesis)
Terbinafine:
-use: dermatophytes
Naftifine:
-used for topical tinea corporis, cruris, and versicolor.
Imadazole class:
-MOA
Clotrimazole
-used for what types of infections?
Miconazole:
-used for what types of infections?
Ketoconazole:
-used for what types of infections?
Econazole:
-used for what types of infections?
MOA: inhibits the enzyme necessary for the conversion of lanosterol to ergosterol. lack of ergosterol disrupts fungal membrane leading to inhibition of fungal growth.
Clotrimazole:
-use: tinea corporis pedis, cruris, versicolor
miconazole:
- use: same as clotrimazole, plus vaginal infections d/t candida albicans.
Ketoconazole:
-use: cream tx tinea and candida, shampoo used for seborrheic dermatitis
Econazole:
-use: tinea!!
OTHER CLASS:
Ciclopirox Oxamine:
- MOA
- used for what types of infections?
Selenium sulfinde:
-used for what types of infections?
Tolnaftate:
-used for what types of infections?
MOA: interferes with cell membrane transport and fungal respiratory process.
Use: dermatophytes, C. albicans, tinea versicolor**, oonychomycosis
Selenium sulfide:
-used to treat seborrheic dermatitis and tinea versicolor
Tolnaftate:
-used for tinea versicolor and ALL dermatophyte fungi, INEFFECTIVE against Candida albicans.
What are the Acne preparations?
Azelaic acid Benzoyl Peroxidase Retinoids topical abx dapsone
Azelaic acid:
- MOA
- SE
- preparations
MOA: clears acne by reducing the populations of P, acnes, decreasing the abnormal shedding of skin cells and reducing inflammation.
SE: dry skin and lightening of the skin where applied
Preparations:
- azelex
- finacea
- both are gel or cream
Benzoyl Peroxide:
- MOA
- perparations
- SE
MOA: kills p. acnes, NO INFLAMM PROPERTIES.
Preparations: gel, lotion. cleanser, cream, wash
SE: skin irritation, bleach, hair, allergic rxn.
Topical Retinoids for ACNE:
- MOA
- SE
- drugs
- what medication can you NOT take with these?
MOA: derivative of vit A and are primarily anti-inflamm. Unclog pores and prevents open/closed comedones.
SE: irritate skin, erythema, dryness, increased sun sensitivity
CORNERSTONE OF ACNE TX
Drugs:
-retinoic acids (retin A)
Cannot take Benzoyl peroxidase with retinoids b/c the BP oxidizes the retinoid.
ANTIBIOTICS FOR ACNE
Clindamycin:
-used for what types of acne infection?
Erythromycin:
-monotherapy?
Sodium Sulfacetamide:
- used for what types of infections?
- dont use in which pts?
Clinda:
-good activity against propionibacterium acnes.
Erythromycin:
-No monotherapy d/t high bacterial resistance
Sodium sulfa:
-acnea vulgaris and acnea rosacea.
dotn use in those with sulfa allergies.
Dapsone:
- MOA
- adverse SE?
MOA: anti-inflamm and antibacterial
SE; if appying with benzyle peroxide can turn the skin orange.
What are the topical meds for parasitic infections?
permethrin cream
lindane lotion
ivermectin
Permethrin cream:
- used to treat what parasitic infections?
- how do you use this?
Used to tx lice and scabies, applied to the entire body, leave on for 8-12hrs.
Permethrin cream rinse: has to be reapplied after 14days for the most successful treatment.
Ivermectin:
-drug administration
PO, 2 doses given a week apart.
What are the topical immunosuppressives?
Topical calcineurin inhibitors:
- Tacroliums (Protopic)
- Pimecrolimus (Elidel)
Topical calcineurin inhibitors:
- MOA
- use
- BBW
MOA: nonsteroidal immunomodulating agent, inhibits effects of cytokine production and leads to decreased T cell activiy
Use: 2nd line tx for moderate atopic dermatitis involving the face, eyelids, neck, and skin folds.
BBW: decreased activity of T cells there is evidence that they may increase risk of developing lymphomas and skin CA.
What are the topical meds for skin CA and actinic keratosis?
5-FU
Imiquimod
5-FU (Efudex)
- MOA
- use
- results
MOA: interferes with DNA synthesis
Use: actinic keratosis and low grade basal cell skin CA
results: burning, peeling, blistering skin that then falls off. skin is sun sensitive.
* Must use gloves & applicator otherwise it will burn/blister skin.
Imoquimod:
- MOA
- Use
- Effects
- who should not use this?
MOA: promotes apoptosis of skin CA cells
USE: basal cell CA, actinic keratosis, genital warts
effects: burning, peeling, blistering skin that then falls off. skin is sun sensitive, systemic & flu-like illness
SHould not use this if they have another type of CA already.
