6. Dermatologic Pharmacology Flashcards
What is a mixture of half water and half oil with emulsifier, water evaporates, spreads easily, well absorbed, and wash off with water, in tube, better than ointments for oozing/wet skin, lotions are similar although less viscous?
Creams (have preservatives)
What is a mixture of 20% water and 80% oil, feels greasy, are occlusive meaning they stay on the surface and not well absorbed, best for dry skin since trap moisture, provide for more complete absorption of active ingredient, less like to cause allergic reaction?
Ointments
Wash hands for 15-30 seconds, use plain soap, freq handwashing may lead to skin damage and irritation, alcohol based hand disinfection is easier than soap and water but it is not effective againts what bug?
C. Difficile
Emollients such as petrolatum, lanolin, mineral oil and dimethicone form an oily layer on top of the skin that traps water in the skin, humectants such as glycerin, lecithin and propylene glycol draw water into the outer layer of the skin, and what softeners such as urea/allantoin loosen bounds between top layer of cells helps dead skin cells fall off and retain water- smoother feel?
Horny Substance (keratin) Softeners
for normal skin, use a moisturizer that is water based and light nongreasy feel, for dry skin use a heavier oil-based moisturizer with antioxidants/grape seed oil to keep skin hydrated, petrolatum for very dry cracked skin, for oily skin use water based noncomedogenic to limit acne breakouts, for sensitive use chamomile or aloe with no allergens dyes/fragrences, and for what skin should one use oil based with petrolatum, to hydrate skin, with antioxidants or alpha hydroxy acids to combat wrinkles?
mature skin
UVB radiation causes most erythema/sunburn and skin aging and photocarcinogenesis, UVA radiation causes skin aging and cancer, what absorb UV light such as PABA in UVB range, benzophenones, and dibenzoylmethanes active in UVA range for drug induced photosensitivity?
Sunscreens
Sun protection factor = ratio of minimal erythema dose with sunscreen to the minimal erythema dose without sunscreen- FDA allows 50
Antiseptics are used on skins while disinfectants are used on surfaces/objects, what targets cell envelope and has a MOA of cross linkning of proteins and also targets cross linking of macromolecules via a MOA of cross linking proteins in cell envelope and elsewhere in the cell?
Glutaraldehyde
Quarternary amines target the cytoplasmic (inner) membrane, via MOA of generalized membrane damage involving phospholipid bilayers, chlorhexidine also targets the same membrane but has a MOA of low [ ] affect membrane integrity while high [ ] cause congealing of cytoplasm. What two antiseptics target oxidizing agents, causing oxidation of thiol groups to disulfides, sulfoxides and disulfoxides as well as hydrogen peroxide which forms free hydroxyl radicals ?
Halogens and peroxygens, respectively
bleach?
What is a broad spectrum antimicrobial agent widely used in homes and hospital s due to general efficacy on skin (including oral mucosa) and low irritability, inhibits bacterial spore growth, mycobaceriaostatic, active agent against nonsporulating bacteria and yeasts, low activity against viruses, and activity against protozoal trophozoites, less towards cysts?
Chlorhexidine
one antibiotic mechanisms of resistance is what, which is associated with persistent cells that are non-replicative, limited penetration of the abx, antiobiotic neutalization via enzymes, and allows slow growth?
Biofilm production*
FYI: for minor cuts healing by first intention: inflam phase (24h, neutrophils), proliferative phase (3-7d mitoses, granulation, mø, fibroblast, new capillary), remodeling phase (weeks later, see fibrous union/scar)
for large gouges healing by secondary intention- inflam is more intense because there is more necrotic debris, exudate and fibrin to remove, there are larger amounts of granulation tissue, along with fibroblasts causing a **wound contraction
nah
Use of antiseptic wash solutions such as dilute iodine, chlorhexidine or hydrogen peroxide is not necessary on wounds, they potentially impede wound healing, abx tx should be reserved for would that LOOK infected, meaning dont use what on cuts?
Neosporin abx cream not needed- wont prevent bacterial infection
Primary closure of surgical wounds in high risk patients, poor glycemic control is significantly** associated with worse outcomes– a single postop elevated glucose value even in a nondiabetic is associated with increased?
morbidity and mortality
Removing dead tissues promotes wound healing (wound debridement), low pressure irrigation with normal saline is used to flush bacterial/material, surgical debridement for large areas, enzymatic debridement shows mixed results using collagenase, what therapy has negative perceptions but results in liquifaction of necrotic tissue and leaving healthy tissue?
Maggot therapy
Epidermal growth factor does not significantly improve epithelialization, what is the only GF that is platelet derived growth factor that promotes cell proliferation and angiogenesis, the only agent approved for treatment of chronic diabetic foot ulcers BUT has a BBW for malignancy in which more than 3 tubes increases malignant complication 4x?
Becaplermin
Wounds should be kept moist and should not be exposed to air- heal faster, hydrogels are used for debridement stages, foam and low adherence dressings for granulation stage and hydroccolloid and what dressings for epithelialization stages?
low-adherence dressings
Bacitracin is a peptide antibiotic that is active against gram positive organisms, often causes allergic contact dermatitis, but systemic toxicity is rare, neomycin is an aminoglycoside abx that binds 30s to inhibit protein syn, active against gram - orgs, dermatitis and systemic detection rare, what is a peptide abx effective against gram negative orgs, that RARELY causes allergic reactions?
Polymixin B
Topical imidazoles block ergosterol synthesis and have a wide range of activity against dermatophytes and yeasts, efinaconazole is used in onychomycosis tx, ketoconazole (cyp450 inhib) is cream for dermatophystosis and candidiasis or for seb derm, what two azoles are topically used for vulvovaginal candidiasis?
Miconazole
Clotrimazole
SE: stinging/itching/erythema
What topical antifungal is prescription broad spectrum topical antimycotic disrupting macromolecular synthesis, activity against dermatophytes, candida and malassezia, low incidence of SE and contact dermatitis?
Ciclopirox
What topical antifungal selectively inhibits squalene epoxidase a key enzyme for synthesis of ergosterol, highly active against dermatophytes but less active against yeasts, cream can cause local irritation, avoid contact with mucous membranes?
Terbinafine
