24 - Antifungals and Corticosteroids Flashcards
What drug variables determine percutaneous absorption?
o Concentration (concentration more important than volume)
o Lipophilicity
o Molecular size (most effective topical meds have a molecular weight of
What vehicle variables determine percutaneous absorption?
o Lipid content (ointment strongest vehicle, solution typically the weakest) o Irritancy (irritating vehicles will alter skin barrier function)
What skin variables determine percutaneous absorption?
o Stratum corneum thickness
o Cutaneous vasculature
o Inflamed skin (will have increased absorption)
o Ulceration (can get systemic effects)
What other variables determine percutaneous absorption?
o Skin hydration (hydrating skin prior, increases absorption) o Occlusion (applying topical, then wrapping in impervious material, ex – lotion on feet, then wrap in saran wrap) o Age (children have increased total body surface to body volume ratio)
What are the risk factors for systemic toxicity?
- Time
- Surface area
- Body site
- Skin barrier function
- Use of occlusion
- Inappropriate use
What are the consequences of systemic toxicity in corticosteroids, silver products and antibiotics?
Corticosteroids
o Altered HPA axis
Silver products
o Renal or hepatic problems
Antibiotics
o GI effects, renal effects
Describe the spectrum of inflammation and the cooresponding spectrum of dermatologic vehicles
INFLAMMATION
Acute inflammation
o Erythema, edema, vesiculation, oozing, crusting, infection, puritus
Chronic inflammation
o Erythema, scaling lichenification, dryness, puritus
TREATMENT
Appropriate treatments o Wet dressing (solutions) o Powders, lotions, aerosols, sprays o Creams (oil-in-water emulsions), gels o Ointments (water-in-oil emulsions, inert bases)
This means that with acute inflammation, wet dressings and powders/lotions are more appropriate, but as you progress to chronic inflammation, creams and ointments will be needed
What are the general treatment axioms
- If wound is wet, dry it
- If wound is dry, wet it
- If wound is inflamed/irritated, soothe it
- If chronic wound is stagnant, irritate/turn into chronic wound
What are the types of topical medications and vehicles we can use?
- Open Wet Dressings
- Closed wet dressings
- Powders
- Lotions
- Cream
- Gel
- Ointment
Describe open wet dressings and closed wet dressings
Open Wet Dressings
o Causes vasoconstriction and decreased inflammation
o Cleanse wound of exudates, crusts, and debris
o Indication: acute inflammatory conditions, erosions, and ulcers
Closed wet dressings
o Can cause maceration
Describe powders, lotions, creams, gels and ointments
Powders
o Used to reduce moisture, maceration, and friction
Lotions
o Suspension of powder in water (can be a little too drying for some skin)
Cream
o Semisolid emulsion of oil in water (much more hydrating than a lotion)
Gel
o Semisolid emulsion that liquefies on contact, leaving thin film
Ointment
o Water droplets suspended in oil or petroleum
Describe the relative potency, hydration/drying properties, stage of dermatitis treated, sites to avoid and sensitization risk for OINTMENTS
- Relative potency = strong
- Hydration/drying properties = hydrating
- Stage of dermatitis treated = chronic
- Sites to avoid = sites with maceration
- Sensitization risk = very low
Describe the relative potency, hydration/drying properties, stage of dermatitis treated, sites to avoid and sensitization risk for CREAMS
- Relative potency = moderate
- Hydration/drying properties = some hydration
- Stage of dermatitis treated = acute to subacute
- Sites to avoid = sites with maceration
- Sensitization risk = significant
Describe the relative potency, hydration/drying properties, stage of dermatitis treated, sites to avoid and sensitization risk for GELS
- Relative potency = stong
- Hydration/drying properties = drying
- Stage of dermatitis treated = acute to subacute
- Sites to avoid = fissures, erosions
- Sensitization risk = significant
Describe the relative potency, hydration/drying properties, stage of dermatitis treated, sites to avoid and sensitization risk for LOTION/SOLUTION
- Relative potency = low
- Hydration/drying properties = variable
- Stage of dermatitis treated = acute
- Sites to avoid = fissures, erosions
- Sensitization risk = significant
Describe “fingertip unit” prescription amounts
Ointment expressed from tube from index finger MPJ to tip of finger
- Approximately 0.5 grams
- 1 FTU Should cover plantar aspects of 1 or both feet
- Need 2 FTU to cover one foot
- If just doing interspaces, should only need 0.25-0.5 FTU or 0.1-0.25 grams
For most podiatric applications a 15 gram tube will last 1 month
- If prescribing for several months, use 60 gram tube because it is less expensive
Common topicals used in podiatry
Most common
o Antibiotics
o Antifungals
o Corticosteroids
Less common
o Antivirals
o Pain medications
Topical antibiotics
- Most commonly in cream or ointment form
- Solutions occasionally used for soaking (Dakin’s, acetic acid, Burrow’s)
- Antiseptics (for surgical preparation and scrub)
Topical antibiotics - creams and ointments
- Bacitracin
- Polysporin
- Neosporin
- Mupirocin (bactroban)
- Gentamicin
- Silvadene
Bacitracin cream/ointment
Contains one abx – bacitracin
Coverage
- Good Gram (+) coverage, minimal to no gram (-) coverage
- Can cause sensitivity reaction, particularly with stasis dermatitis
Polysporin cream/ointment
Contains 2 abx – bacitracin and polymyxin B
PolymyXin B effective against gram (–)
- Including pseudomonas
- Contact allergy rare
This is her number one choice – don’t need the third one because of problems (below)
Neosporin cream/ointment
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
Mupirocin (bactroban) cream/ointment
o Effective against MRSA
o Can be used in nasal passages for MRSA carriers
Gentamicin cream/ointment
o Good gram (-) coverage, notably Pseudomonas
Silvadene cream/ointment
o Effective against Gram (+) and (-)
o Shouldn’t use in patients allergic to sulfonamides
o If using in large area over long time period, can get significant absorption of silver
o Can occasionally cause brown/gray hyperpigmentation of skin with use
o Commonly used with burn patients
Topical antibiotic solutions
- Dakin’s solution
- Acetic acid solution
Dakin’s solution
o Sodium hypochlorite solution – AKA bleach
o Comes in 0.5%, 0.25%, or 0.125% strengths
Acetic acid solution
o 5% solution (pretty much just vinegar)
o Effective against superficial pseudomonas infections
o Also has drying effect – Good for wet tinea pedis infection
Astringent solutions
- Burow’s solution
- Epsom salt
Burrow’s solution
o 1:40 mixture or 0.14% aluminum acetate solution
o Used to dry out wounds – i.e. macerated tinea pedis or wet dermatitis
Epsom salt solution
o Magnesium sulfate
o 2 Tbsp./pint of H2O
o Also used for drying effect
Topical antiseptics
Used for presurgical scrub for surgeon and/or patient
o Chlorhexidine
o Povidone-Iodine
Over the counter antibacterial soaps
- Triclosan
Chlorohexidine antiseptic
- Broad spectrum coverage
- S. aureus, P. aeruginosa, S. marcescens, and facultative anaerobes
- Low rate of sensitization
Povidone-Iodine antiseptic
- Broad spectrum against gram (+) and (-)
- High incidence of dermatitis
- Can also be used as a topical to help dry wounds
Triclosan antibacterial soap
- Most common abx soap ingredient
- Broad spectrum activity
Antifungal classes
- Polyenes (not used much in podiatry)
- Azoles (older class, mostly fungistatic)
- Allylamines/benzylamines (newer class, better potency/efficacy, fungicidal, can actually kill fungus)
- Others (ciclopirox (loprox))
Polyenes
Nystatin
o Effective against Candida albicans
o Not highly effective against dermatophytes, bacteria, or viruses
Remember - not commonly used in podiatry
General characteristics of azoles
o Azoles are effective against dermatophytes
o We are not responsible for dosing information, but just from a clinical perspective, some agents will be more effective if they only need to apply it once a day, just from the compliance perspective
List of azoles
- Miconazole (Monostat-Derm, Micatin)
- Clotrimazole (Lotramin)
- Econazole (Spectazole)
- Ketoconazole (Nizoral)
- Sertaconazole (Ertaczo)
- Oxiconazole (Oxistat)
- Efinaconazole topical (Jublia)
Miconazole (Monostat-Derm, Micatin)
o Good activity against T. rubrum, T. mentagrophytes
o Has mild effectiveness against some Gram (+)
Clotrimazole (Lotramin)
o Broad spectrum against, Trichophyton, Epidermophyton, and Microsporum
o Also active against Gram (+) and Candida
Econazole (Spectazole)
o Broad spectrum against Trichopyton, Microsporum, Epidermophyton, C. albicans, and M. furfur
o Shows some gram (+) and (-) coverage
Ketoconazole (Nizoral)
o Broad spectrum activity against dermatophytes
Sertaconazole (Ertaczo)
o Relatively lipophilic
o Effective against T. rubrum, T. mentagrophytes, E. floccusum, Candida
o Moderate activity against Gram (+) bacteria
Oxiconazole (Oxistat)
o Good absorption into stratum corneum, will stay for several days after treatment
Efinaconazole topical (Jublia)
o 10% solution
o Used for onychomycosis
o Needs to be used QD for 48 weeks (LONG time)
List of allylamines and benzylamines
- Naftifine (Naftin)
- Terbinafine (Lamasil)
- Butenafine (Mentax)
Naftifine (Naftin)
o Highly lipophilic, allows good penetration and high concentration in stratum corneum
o Expensive
o Earlier symptomatic relief than Lotramin
Terbinafine (Lamasil)
o Highly lipophilic and binds well to stratum corneum
o Broad spectrum against dermatophytes, molds, C. albicans
o Effective against chronic tinea pedis
Butenafine (Mentax)
o Broad spectrum against dermatophyes and dimorphic fungi
Other antifungals
Ciclopirox Olamine (Loprox, Penlac Nail Lacquer)
Ciclopirox Olamine (Loprox, Penlac Nail Lacquer)
o Used for tinea pedis or onychomycosis
o Has Gram (-) and (+) activity as well as anti-inflammatory properties (good for tinea pedis with secondary bacterial infection)
o Lacquer shown to have 40% clinical and mycological efficacy (have to use daily for several months)
Anti-dermatophyte potnecy
From MOST to LEAST potent
- Butenafine (Mentax) = Terbinafine (Lamasil)
- Ciclopirox (Loprox)
- Naftifine (Naftin)
- Azoles
Propylene glycol content in topical antifungals
- If there is irritation, maybe switch to something that is propylene and glycol free
- Note that the more potent ones have the propylene and glycol in them
Antifungas WITHOUT propylene glycol
- Miconazole (Micatin)
- Clotrimazole (Lotrimin)
- Econazole (Spectazole)
- Naftifine (Naftin)
- Ciclopirox (Loprox)
Antifungals WITH propylene glycol
- Terbinafine (Lamasil)
- Butenafine (Mentax)
- Ketoconazole (Nizoral)
- Oxiconazole (Oxistat)
Mechanism of action/anti-inflammatory effects of topical corticosteroids
Reduces number and function of inflammatory cells and chemical mediators
o Reduced inflammation and immune response
Reduces keratinocyte proliferation, fibroblast activity, and dermal volume(due to decreased H2O content)
o Thinning of the skin
o Prolonged use causes skin atrophy
Indications for topical steroids
- Inflamed or irritated skin, non infectious in nature*
- Examples: dermatitis, eczema, psoriasis, lichen planus
Contraindications for topical steroids
Absolute
o Hypersensitivity to the topical corticosteriod or vehicle
Relative
o Bacterial, fugal, or viral infection
o Ulceration (higher chance of systemic effect of steroids)
Systemic adverse effects of topical corticosteroids
o Suppression of HPA axis
o Iatrogenic Cushing’s syndrome
o Growth retardation in infants and children
Local adverse effects of topical corticosteroids
o Epidermal atrophy o Steroid rebound o Allergic or contact dermatitis o Exacerbation or increased susceptibility to bacterial, fungal and viral infections o Reactivation of Kaposi’s sarcoma o Delayed wound healing o Tachyphylaxis (tolerance to med)
Risk factors for systemic effects of topical corticosteroids
o Infant or child o Liver or renal disease o Amount applied o Potency o Use of occlusion o Lack of physician supervision
Risk factors for local atrophy due to topical corticosteroids
o Infant or child o Potency o Duration of treatment o Use of occlusion o Location (face, neck, axilla, groin, upper inner thighs, pretibial location)
Absorption of topical corticosteroids
- About 1% of TCS will be absorbed on normal forearm skin (less on thick skin like sole of foot)
- This will increase if skin irritated, inflamed, or thinned
- Placing under occlusion dramatically increases absorption (Increases skin surface area by 40%)
Choosing a topical corticosteroid - factors to consider
- TCS potency
- Vehicle
- Brand name vs Generic
- Price and cost-effectiveness considerations
- Proper amount to dispense
- NOTE: Choose the least potent topical that will still be affective, or quickly taper down
Potency classes of topical corticosteroids
- Very High (I)
- High (II &III)
- Medium (IV & V)
- Low (VI &VII)
Very high (I) potency of topical corticosteroids
o Short term use only
o Best for thick, lichenified or hypertrophic skin resistant to high potency topical steroids
High (II &III) potency of topical corticosteroids
o Severe dermatitis, thick, lichenified, or hypertrophic skin
o Short term use only
Medium (IV & V) potency of topical corticosteroids
o Moderate dermatitis
o Good for extremities as long as not on extremely thickened skin
Low (VI &VII) potency of topical corticosteroids
o Mild dermatitis
o Preferred treatment for large areas
o Best if long term treatment required
o Best for thin skin
List of very high (I) potency corticosteroids
o Amcinonide ointment 0.1% (Cyclocort)
o *Betamethasone dipropionate ointment 0.05% (Diprosone)
o *Desoximethasone cream 0.25% (Topicort)
o *Desoximethasone gel 0.05% (Topicort)
o Diflorasone diacetate ointment 0.05% (Florone)
o Fluocinonide 0.06% (Lidex)
o Halcinonide cream 0.1% (Halog)
List of potent (II) corticosteroids
o *Betamethasone benzoate gel 0.025% (Benisone)
o *Betamethasone dipropionate cream 0.05% (Diprosone)
o *Betamethasone valerate ointment 0.1% (Valisone)
o Diflorasone diacetate cream 0.05% (Florone)
o Triamcinolone acetonide cream 0.5% (Aristocort)
List of mid-potency (III) corticosteroids
These are a lot of LOTIONS (change of vehicle = change of potency)
o Amcinonide cream 0.1% (Cyclocort)
o Betamethasone valerate lotion 0.1% (Valisone)
o Flucinolone acetonide cream 0.2%, ointment 0.025% (Fluonid, Synalar)
o Hydrocortisone valerate cream 0.2% (Westcort)
o *Triamcinolone acetonide ointment 0.1% (Aristocort, Kenalog) - Still a prescription, but a lower potency for those who need to apply over a large area – comes in a large jar (not tiny tube)
List of low potency (IV) corticosteroids
o Aclometasone dipropionate cream 0.05% (Aclovate)
o Betamethasone valerate cream 0.1% (Valisone)
o Clocortolone pivalate cream 0.1% (Cloderm)
o Fluocinolone acetonide cream 0.025% (Fluonid, Synalar)
o Flurandrenolide 0.05% (Cordran)
o Hydrocortisone valerate cream 0.2% (Westcort)
o Triamcinolone acetonide cream 0.01%, lotion 0.025% (Kenalog, Aristocort)
List of mild (V) corticosteroids
Mostly OTC
o Desonide cream 0.05% (Tridesilon)
o Flumethasone pivalate cream 0.03% (Locorten)
o Fluocinolone acetonide solution 0.01% (Fluonid, Synalar
List of least potent (VI) corticosteroids
OTC
o Prednisolone 0.5% (Meti-derm)
o Methylprednisolone 1% (Medrol)
o Fluorometholone 0.025% (Oxylone)
o Dexamethasone 0.1% (Decadron Phosphate)
o *Hydrocortisone 0.25, 0.5, 1.0, 2.5% (Hytone, Nutraderm, Synacort)
Combination therapy options
- Corticosporin
- Lotrisone
Corticosporin
o Neomycin + Polymyxin + Hydrocortisone
o Corticosteroid-responsive dermatoses with secondary infection
Lotrisone
o Clotrimazole + Betamethasone
o Inflamed tinea pedis
Anti-hyperkaratotics
- Used for patients with severe chronic hyperkaratosis
- Helps to hydrate, soften and debride thickened skin
Lactic acid
o Lac-Hydrin, Amlactin
o 12% Cream or Lotion
o May cause irritation in non-intact skin
Urea
o Carmol 40
o 40% urea cream, lotion, gel
