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