Dermatology Flashcards
How long does it take for a cell to fully keratinze?
- 30d
What are the pharmacological variables?
- variation in drug penetration (i.e. thin skin)
- conc. gradient
- dosing schedule
- vehicles & occlusion
- allergies/sensitivities
What is the relationship between concentration of drug and absorption?
- directly, [high], high absorption
What are the two types of topical drugs?
- moisturizing
- drying
Patient has xerosis, lichenification, or scaling - what type of topical drug should you rx?
- moisturizing
Patient has a weeping, oozing, vesicular lesion with crusting - what type of topical drug should you rx?
- drying
What must you take into consideration when administering topical rxs?
- hairy areas
- cosmetic feel/look
What are the general uses for topical steroids?
- nonspecific anti-infalm
- reduces itching
What do low/medium dose topical steroids tx?
- eczema
- irritant dermatitis
- seborrhea
- atopic dermatitis
What do high dose topical steroids tx?
- psoriasis
- lichen planus
- allergic contact dermatitis
What is the MOA of topical steroids?
- decrease migration of PMNs & fibroblasts
- reverses cap permeability
- controls rate of protein synthesis
- lysosomal stabilization
What must you remember about using ultra high potency steroids?
- should not be used >3w
What must you remember about using low, medium, or high potency steroids?
- should not be used >3m
What should be taken into considerations when using topical steroids?
- chronic use effects
- low doses used on areas of increased absorption
- caution with occlusive dressings
What type of topical steroid has the highest effects?
- ointments
What is the ADME of topical steroids?
- A: minimal systemic
- D: highly protein bound
- M: hepatic
- E: urine
What is the 1/2 life of topical steroids?
- 6.5h
What does the A (administration) depend on for topical steroids?
- potency
- formulation
- extent of use
- area of use
What is the common ADE (adverse drug effect) of topical steroids?
- cutaneous atrophy, can have teleangiectases & purpura, resolves
What are the other/serious ADEs of topical steroids?
- striae
- acne
- refractory rosacea
- hypopigmentation
- alopecia
- glaucoma
Describe the relationship between topical steroids & adrenal suppression/iatrogenic Cushings
- specific ADE of topical steroids
- increased with dose/duration and in children
What are the drug interactions of topical steroids?
- none when topical
What are the contraindications of topical steroids?
- systemic fungal infection
- hypersensitivity
What patient populations should use caution with topical steroids?
- preggers
- children < 12y/o
What is the next step in a patient who is on topical steroids but continues to have worsening symptoms?
- ? fungal
What improves cutaneous absorption of topical steroids?
- hydration
i. e. apply s/p shower or cold compress
What is the fingertip method?
- 1 fingertip amount will cover 2 palms
- fingertip = 0.5g
( 2 palms divided by 1 fingertip = 1/2 g)
Where is psoriasis mostly located?
- elbows
- knees
- back
- scalp
Define mild-moderate psoriasis
- <5%BSA
Define moderate-severe psoriasis
- > 5% BSA
OR - hand, feet, face or genitals
What is the MOA of corticosteroids?
- inhibits inflammation
What are the topical medications for psoriasis?
- corticosteroids
- vit D analogues
- tazarotene
- calcineurin inhibitors
What is the MOA of vit D analogues?
- bind to Vit D receptor
- promotes differentiation of keratinocytes
What ADE can vit D analogues cause?
- photosensitivity
What is the MOA of tazarotene?
- binds to retinoic acid receptors
- normalizes epidermal differentiation
side note of tazarotene?
- photosensitivity
- pregnancy category X
What is the MOA of calcineurin?
- inhibits transcription of cytokines including IL-2
What can calcineurin be used for specifically?
- facial or intertriginous psoriasis
When are topical medications used in psoriasis?
- mainly mild disease
What is the first line tx for psoriasis?
- corticosteroids (generally)
_______ + _______ more effective than _______
- calcipotriene
- corticosteroid
- monotherapy
What are the oral non-biologics for psoriasis?
- methotrexate
- cyclosprorine
- acitretin
- fumaric acid esters
- apremilast
In general, what do many non-biologics have?
- many contraindications (CI)
What is the MOA of methotrexate?
- blocks dihydrofolate ==> blocks DNA synthesis
What is the MOA of cyclosporine?
- inhibits IL-2 & other cytokines
When a patient is being treated with oral non-biologics, what must be watched?
- frequent lab monitoring
When should patients with psoriasis be referred?
- once oral therapy is indicated
What is the stratum corneum also known as & what is its function?
- drug reservoir
- extends 1/2 life
What are the concentrations/potencie of topical steroids?
- lowest
- low
- medium
- high
- highest
What are the biologics for psoriasis?
- adalimumab (Humira)
- etanercept (Enbrel)
- infliximamb (Rmicade)
- alefacept (Amevive)
- ustekinumab (Stelara)
What is a concern for psoriatic biologics?
- serious infection
What must be obtained prior to biologics?
- neg. PPD
Who manages biologic rx’s?
- specialist
What is a non-pharmacologic tx for psoriasis?
- UVB from phototherapy
What is the 1st line tx for mild (grade I) acne?
- topical retinoids consider with antimicrobial (i.e. benzoyl peroxide)
What is the 1st line tx for moderate (grade II & III) acne?
- topical retinoid + oral abx w/ or w/o antimicrobial (i.e. benzoyl peroxide)
What is the 1st line tx for severe (grade IV) acne?
- oral isotretinoin
What is the MOA of topical retinoids?
- prevents formation of comedones & inflam lesions
- does not contribute to bacteria resistance
T/F: There are concerns surrounding topical retinoids and long-term use.
- false
How are topical retinoids available?
- gel
- cream
- sol’n
- lotion
- ointment
- compress
What are the ADEs of topical retinoids?
- skin peeling
- redness
- dryness
- burning
- puritis
What patient population should topical retinoids be avoided in?
- preggers
What other product should be used with topical retinoids?
- daily moisturizer with sunscreen
What are examples of topical keratolytics?
- benzoyl peroxide
- salicyclic acid
What is the MOA of topical keratolytics?
- rapid shedding of epidermis to prevent clogging & formation of comedones
- topical antimicrobial, not associated with resistance
What is the optimal preparation of topical keratoylitcs?
- gel
What are the ADEs of topical keratolytics?
~local effects~
- skin irritation
- contact dermatitis
- dryness erythema
- peeling
- stinging
What are examples of antimicrobial therapy for acne?
- dapsone
- erythromycin
- clindamycin
- tetracycline
- minocycline
What is the MOA of antimicrobial therapy for acne?
- decrease bacterial load
- reduce inflammation
When can antimicrobials be used PO?
- severe
How are antimicrobials used?
- combo with benzoyl peroxide
What is the ideal length for antimicrobials PO?
- 3mo
What should be avoided with topical antimicrobials?
- combining with oral
- switching abx w/o justification
How does isotretinoin tx acne?
- reduces sebum production
- reduces comedone formation by decreasing keratinization
- reduces P. acnes
- reduces inflmmation
What are the ADEs of isotretinoin?
- excessive drying, burning, & skin inflam
- mild lip inflam
- dyslipidemia
- arthralgias/musculoskeletal pain
What must be avoided with isotretinoin?
- pregnancy
What is the preferred route of rx admin for urticaria?
- PO
Which type of anithistamines is preferred and why?
- 2nd generation: effective with no/minimal drowsiness
What is the 1st line tx for urticaria?
- 2md generation antihistamines
What is the 1st line tx for impetigo?
- prevention
What is the rx tx for impetigo?
- broad spectrum abx
- topical is usually sufficient
What is the treatment for topical fungal infections?
- suffix: -azole
- allylamines
- others rare: ciclopirox, griseofulvin
What is the MOA of -azoles?
- inhibits conversion of lanosterol to ergosterol via CYP P450 (prevents fungal cell wall synthesis)
- also affects human steroid synthesis
What is the MOA of allylamines?
- inhibit squalene oxidase, required for ergosterol synthesis
- less effect on human steroid synthesis
What is the MOA of griseofulvin?
- binds to fungal microtubules & inhibits mitosis
What is the MOA of ciclopirox?
- not well understood
- blocks cell membrane transport, depeleting cells of substrates and ions
What is a major concern with -azoles?
- CYP P450 drug interactions
What type of ADEs are seen with the topical fungal rxs?
- mainly local
When is topical tx used for viral infections (HSV)?
- mild lesions such as cold sores
When is oral tx used for viral infections (HSV)?
- genital lesions
- severe
- suppression (prophylaxis of breakouts)
What is the group of rxs used as common antivirals?
- suffix: -clovir
i. e. acyclovir, famciclovir, valacyclovir
What is the MOA of antiviral rxs?
- inhibit viral DNA synthesis
- should resolve sx in 7d
What must be avoided with antiviral rx tx & why?
- OTC creams, delay healing & increase transmission of disease
What are the side effects of topical antivirals?
- urticaria
What are the side effects of oral antivirals?
- GI irritation
- elevated LFTs
- disorientation
- hallucinations
- H/A
What is an antiviral safety concern?
- drug & vaccine interactions
What are the ‘top’ 4 types of moisturizing topicals?
- ointments
- foams
- creams
- pastes
What are the ‘top’ 4 types of drying topicals?
- tinctures
- wet dressings
- lotions
- gels