Dermatology Pharm

topical agents

skin is used as a point of entry to the systemic circulation which bypasses the liver and thus avoids first pass metabolism

Layers of the epidermis

1. (outermost) stratum corneum—can form reservoir that can delay absorption

2. stratum lucideum

3. stratum granulosum

2. stratum spinosum

3. stratum basale

Layers of the skin:

1. epidermis

2. dermis (sweat glands)

3. hypodermis (adipose layer)

topical antibiotics

only used for minor dermal conditions, treatment of acne, and anti-inflammatory properties

tavaborole and ciclopirox

The only effective topical treatment for onychomycosis

imquimod

a topical immunomodulator that stimulates interferon alpha and stimulate the local production of interleukin production and TNF; T

Tacolimus

Topical calcineurin inhibitor that prevent the release of inflammatory cytokines and inhibit T lymphocyte activation; used for Atopic dermatitis

Tretinoin/adapalene

increase the activity of RNA polymerase and that results in a decreased cohesion between the epidermal cells, increasing cell turnover

benzoyl peroxide

an acne treatment whose mechanism is antimicrobial, but can be irritating and drying to the skin

Brimodine

used for acne rosacea (topical alpha agonists); decreases redness by causing vasoconstriction

topical corticosteroids

MOA is to decrease the concentration, distribution and function of peripherical leukocytes and anti-inflammatory cytokines; decrease the inflammatory response; cause vasoconstriction when applied topically; be concerned about atrophy; absorption increases with inflammation and occlusion after application

salicylic acid

a destructive keratolytic agent used break down the outer layer of skin to treat warts, lower concentrations are used to treat acne;

MOA-not completely understood

Urea

a keratolytic agent that pulls moisture into the stratum corneum and can soften skin (calluses); higher concentrations can be destructive and can be used for hyperkeratosis and nail beds prior to nail removal

podofilox

a keratolytic agent used specifically for warts; after absorption, it prevents the formation of the mitotic spindles preventing cell division

fluorouracil

a destructive topical agent; lower strengths used for actinic keratoses and superficial basal cell carcinoma treatment; inhibits the enzyme Thymidylate synthase, which is responsible for building thymidine used for building DNA, creating a shortage of building blocks for DNA which leads to cell death

Doxepin

a topical antipruritic that blocks the histamine receptors in the skin

Pramoxetine

a topical antipruritic and local anesthetic by blocking the initiation and conduction of nerve impulses from the skin

Topical estrogen patches

designed to release the drug at a specified rate, and can be switched out every 7 days, bypassing liver effects seen with the oral version

Topical testosterone patch

oral is associated with hepatic dysfunction, so the topical avoids this side effect; similar to estrogen patch

Fentanyl patch

an opiod analgesic for pain; high concentration in the patch to create a gradient to absorb through the stratum corneum; 12 hours until pt feel pain relief and reservoir allows med to still be absorbed even after patch removal;

used patches must be monitored as drug is still available even after removal