Dermatologic Agents Flashcards
skin penetration of an agent is affected by what factors?
Decreased molecular size, increased lipid content, increased drug concentration, skin integrity, skin thickness, surface area of application
Polymyxin B- Neosporin/ Neomycin
Topical anti microbial used for prophylaxis of infection after injury
MOA: bactericidal, interacts with phospholipids and disrupts the cell membrane (bacitracin interacts with cell wall peptidoglycans)
Char: ointment, can be mixed with corticosteroids
SE: some local irritation, anaphylaxis rare, ototoxic (AVOID using optic applications there is possible perforated TM)
Mupirocin/ Bactroban
Topical antibiotic
Indic: impetigo, highly active against staph, strep, MRSA (not effective against fungal/viral infx)
MOA: inhibits bacterial protein synthesis
Char: ointment, BID/ TID dosing
Apply to nares in MRSA Tx to avoid carriage status
SE: local irritation with burning, itching, local pain/ rash
Ketoconazole/ Nizarol
Topical antifungal
Indic: Tinea pedis, tinea cruris, tinea corporis, seborrheic dermatitis, superficial yeast infx
MOA: inhibits sterol synthesis
SE: local irritation
Char: topical ointment, PO available for systemic infx
In order to have a systemic effect, topical drug agents need to penetrate what layer of the skin?
Stratum corneum
How are glucocorticoids rated for relative strength? What class of glucocorticoids are considered to be the strongest?
Class 1-7; 1 is most potent, 7 is least potent
Halogenated corticosteroids are considered to be the most potent
Glucocorticoid side effects
Striae, skin atrophy, telangectasia, purpura, acneiform lesions, perioral dermatitis, overgrowth of skin fungus/bacteria, hypopigmentation, rosacea, suppressed HPA axis, inc risk hyperglycemia, osteoporosis, osteonecrosis
Atrophy of fat, muscle at injection site in IM applications
What are factors that can affect systemic corticosteroid absorption?
Increased absorption at inflamed skin Amount applied Size of area to be treated Frequency of application Length of tx Drug potency Barrier use
Hydrocortisone/ Cortef
Class: glucocorticoid/ corticosteroid
Indic: atopic dermatitis, contact/ allergic dermatitis, psoriasis, eczema, pemphigus, SLE, granulomatous dz, sarcoidosis
MOA: anti-inflammatory, affects gene transcription
Char: cream, ointment, PO/IV/IM; minimize use on face/ thin skin
What kinds of processes do retinoids affect?
Cellular proliferation, differentiation, immune function, inflammation, sebum production
What are some indications for retinoids?
Cystic/papular acne, basal cell ca, squamous cell ca, actinic keratosis, psoriasis, cutaneous aging
What are some etiologies for acne?
Follicular hyperkeratosis Bacteria (probionoibacterium acnes) Increased inflammation Increased sebum production Androgens
What is the general initial treatment for acne? What is a secondary treatment option if acne is refractory to initial tx?
Initial tx: TOPICAL salycylic acid, benzoyl peroxide, erythromycin, clindamycin, metronidazole, retinoids (tretinoin)
Secondary Tx: ORAL tetracycline, retinoids (accutane)
Tretinoin/ Retin A
Class: vitamin A derivative
Indic: acne, photodamaged skin
MOA: dec hyperkeratinization, inc epidermal thickness, inc dermal collagen production
Char: topical 0.01-0.1% qd in hs
May take months to see effects
SE: erythema, peeling, burning, stinging, photosensitivity
Isoretinoin/ Accutane
Class: vitamin A derivative
Indic: acne, acne rosacea, hydradenitis supperativa
MOA: dec hyperkeratinization, dec # sebaceous glands, doc sebum production, dec p.acnes bacterium
Char: PO; acne recurs 40% of the time within 6 months of discontinuation
SE: teratogenic, esp in the first 3 months! Also depression, suicidal ideation, psychosis, suicide, HA, myalgias, arthralgias, hyperlipidemia, fatty liver disease, hepatitis, pancreatitis
CI IN PREGNANCY recommended that female pt of childbearing age use two forms of contraceptive
