24: Dermatology Therapeutics - Frush Flashcards
percutaneous absorption variables
- concentration more important than volume
- lipophilicity
- molecular size (most effective topical meds have molecular weight of less than 1000)
strongest percutaneous absorption vehicle
ointment
- solution is typically the weakest
will inflamed skin increase or decrease absorption?
increase
indications for open wet dressings
acute inflammatory conditions, erosions and ulcers
- causes vasoconstriction and decreased inflammation
- closed wet dressings can cause maceration
- used to reduce moisture, maceration, and friction
- suspension of powder in water
- semisolid emulsion of oil in water
- semisolid emulsion that liquefies on contact, leaving thin film
- water deroplets suspended in oil or petroleum
- powders
- lotions
- cream
- gel
- ointment
clinical comparisons of various vehicles
FTU
fingetip unit
- ointment expressed from tube from index finger MPJ to tip of finger
- approx 0.5 g
- 1 ftu should cover plantar aspects of 1 or both feet
- need 2 ftu to cover one foot
antibiotic solutions used for soaking
dakin’s
- sodium hypochlorite aka bleach
acetic acid
- drying, good for wet tinea pedis, effective against sueprficial pseudomonas infections
burrow’s
- aluminum acetate solutions, dry out wounds
epsom salt
- magnesium sulfate, drying effect
Bacitracin
▪Good Gram (+) coverage
▪Minimal to no gram (-) coverage
▪Can cause sensitivity reaction, particularly with stasis dermatitis
Polysporin
- Contains 2 abx – bacitracin and polymyxin B
- PolymyXin B effective against gram (–)
- Including pseudomonas
- Contact allergy rare
Neosporin
Contains 3 abx – bacitracin, polymyxin B, and neomycin
Neomycin – covers gram (+) and (-)
▪Good S. aureus coverage
▪Does not cover Pseudomonas, or Bacteroides
▪Weak Strep activity
▪1% of population has contact allergic sensitivity, rate can increase to almost 10% in patients with prolonged use
▪Bacitracin causes coreaction with neomycin
Can be used in nasal passages for MRSA carriers
mupirocin (bactroban)
gentamicin
good gram - coverage, notably pseudomonas
silvadene
- Effective against Gram (+) and (-)
- Shouldn’t use in patients allergic to sulfonamides
- If using in large area over long time period, can get significant absorption of silver
- Can occasionally cause brown/gray hyperpigmentation of skin with use
- Commonly used with burn patients
used for presurgical scrub for surgeon and/or patient
topical antiseptics
- chlorhexidine
- povidone-iodine
nystatin
- polyene
- effective against candida albicans
- not used in podiatry much
Miconazole
- azole
- Good activity against T. rubrum, T. mentagrophytes
- Has mild effectiveness against some Gram (+)
- BID x 4 weeks, OTC
clotrimazole
- Broad spectrum against, Trichophyton, Epidermophyton, and Microsporum
- Also active against Gram (+) and Candida
- BID x 2-4 weeks, OTC
Econazole
- Broad spectrum against Trichopyton, Microsporum, Epidermophyton, C. albicans, and M. furfur
- Shows some gram (+) and (-) coverage
- Apply QD
Ketoconazole
- Broad spectrum activity against dermatophytes
- BID x 6 weeks
Sertaconazole
- Relatively lipophilic
- Effective against T. rubrum, T. mentagrophytes, E. floccusum, Candida
- Moderate activity against Gram (+) bacteria
- Apply BID for 4 weeks
oxiconazole (oxistat)
- Apply QD-BID for 4 weeks
- Good absorption into stratum corneum, will stay for several days after treatment
efinaconazole topical
JUBLIA
- 10% solution
- Used for onychomycosis
- Apply qd for 48 weeks
naftifine (naftin)
- allylamine/benzylamine
- Highly lipophilic, allows good penetration and high concentration in stratum corneum
- Expensive
- Apply QD-BID
- Earlier symptomatic relief than Lotramin
terbinafine (lamasil)
- allyamine/benzylamine
- Broad spectrum against dermatophytes, molds, C. albicans
- Effective against chronic tinea pedis
- Apply BID 1-4 weeks
- OTC
butenafine (mentax)
- allylamine and benzylamine
- Broad spectrum against dermatophyes and dimorphic fungi
- Apply BID x 7 days, or QD x 14 days
what is propylene glycol?
Propylene glycol : Vehicle used in some antifungals to increase penetration. Can cause irritation is some patients.
most potent anti-dermatophyte tx
- Butenafine (Mentax) = Terminafine (Lamasil)
- Ciclopirox (Loprox)
- Naftifine (Naftin)
- Azoles
MOA topical corticosteroids
- ¡Reduces number and function of inflammatory cells and chemical mediators
- Reduced inflammation and immune response
- Reduces keratinocyte proliferation, fibroblast activity, and dermal volume(due to decreased H2O content)
- Thinning of the skin
- Prolonged use causes skin atrophy
indications for topical corticosteroids
inflamed, or irritated skin, non infectious in nature
Examples
- Dermatitis, Eczema, Psoriasis, Lichen planus
Absolute contraindication for topical corticosteroids
Hypersensitivity to the topical corticosteriod or vehicle
Relative: Bacterial, fugal, or viral infection and Ulceration
Antihyperkeratotics
- Used for patients with severe chronic hyperkaratosis
- Helps to hydrate, soften and debride thickened skin
Lactic acid
- Lac-Hydrin, Amlactin
- 12% Cream or Lotion
- May cause irritation in non-intact skin
Urea
- Carmol 40
- 40% urea cream, lotion, gel
Neomycin + Polymyxin + Hydrocortisone
cotricosporin
- used for Corticosteroid-responsive dermatoses with secondary infection
clotrimazoel and betamethasone
lotrisone
- used for inflamed tinea pedis
