Dermatologic Pharmacology Flashcards
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Regional variation of skin in drug penetration
Refers to tendency for scrotum, face, axilla and scalp to be far more permeable than the forearm or thicker skinned areas
The skin has a ___ effect of many drugs allowing for ___ dosing conditions
reservoir, once daily
To maximize effective absorption of drugs thru the skin, sometimes ____ can be very useful for transfer (but may lead to toxicity)
Occlusion
Characteristics of good dermatologic vehicles (3) (vehicles meaning ointments, gels, powders, etc)
- ability to hydrate the stratum corneum
- increased solubility
- increased rate of release
Treat wet lesions with ___ and dry lesions with ____
drying agents, moisturizing agents
topical glucocorticosterois function
Used to relieve inflammation and itching associated with variety of dermatologic disorders
Topical gucocorticoids absorption
Extent is proportional to duration of use and area where preparation has been applied, absorption is higher where skin is easily permeable or inflamed and lower in thicker regions
Topical glucocorticoids ADRs (2)
- local rxns (atrophy of dermis and peidermis)
- systemic toxicity such as growth retardation or adrenal suppression
Keratolytic agents
Drugs that promote the shedding of the stratum corneum layer of skin causing peeling to extensive desquamation
Salicylic acid drug class and function
Keratolytic agent, promotes desquamation by disllolving intracellular cement that binds scales to stratum corneum used in low conc. to treat dandruff, seborrheic dermatitis, acne, psoriasis, warts, and corn
Salicylic acid ADR
-salicylism (same as in aspirin thru absopriton of skin) casuing tinnitus and hyperpnea
Sulfur drug class and function
Promotes drying and peeling to treat acne, dandruff, psoriasis, seborrheic dermatitis, it is a kerotlyitc agents
Benzoyl peroxide function
First line drug employed topically to treat mild to moderate acne, penetrates stratum corneum or follicular openings unchanged converted metabolically within epidermis promoting keratoysis and suppressing growth of P. acnes (does not cause resistance)
Benzoyl peroxide ADR’s (2)
- drying and peeling of skin
- local burning
Often benzoyl peroxide will be used alongside topical ___ or ___
clindamycin, erythromycin
Dapsone function
Topical agent that provides modest decrease in inflammation often as an alternative to benzoyl peroxide
Tretinoin drug class and function
Retinoids, derivatives of vit A, approved for treatment of mild to moderate acne thru decreasing cohesion between epidermal cells remove existing comedones aand preventing formation of new plugs
Isotretinoin (accutane) drug class and function
Retinoid, restricted for treatment of severe nodulocystic acne vulgaris
Isotretinoin (accutane) ADR’s (7)
- nosebleeds
- inflamation of lips
- dryness and itching of skin, nose and mouth
- loss of night vision
- UV sensitivity
- psychological effects
- teratogenic during pregnancy
Isotretinoin (accutane) drug interactions (2)
- Tetracyclines increase risk of psuedotumor cerebri
- vit A can produce generalized intensification of toxicity
iPledge program
FDA mandated program to manage accutane related teratogenicity requires 2 active forms of birth control
Tazarotene (tazorac) drug class and function
Derivative of vitA, used for topical therapy of acne and psoriasis
Women at least 15 who want contraception, have achieved menarche, and do not respond to topical drugs is criteria for…
….PO contraceptive use for acne treatment
Spironolactone (aldactone) drug class and function
Androgen receptor, additional PO contraception for treatment of acne
2 targets of drug therapy in psoriasis
- keratinocytes
- inflammatory cells
Mild to moderate psoriasis drug treaetments (3)
- topical glucocorticoids (most commonly used)
- keratolytic agents
- UV therapy
Moderate to severe psoriasis drug treatments (3)
- methotrexate
- cyclosporine
- IL-23 antagonist
Anthralin drug class and function
DNA synthesis inhibitor, used for topical treatment of psoriasis
Tars drug class and function
DNA synthesis inhibitor, used in combinations to treat plaque type psoriasis despite unpleasant odor and irritation
Calcipotriene and calcitriol drug class and function
Analogs of D3, topical prep for mild to moderate psoriasis applied BID to affected skin suppresing cell differentiation
Tazarotene gel drug class and function
Retinoid, marketed for use to patients with stable mild to moderate psoriasis
Tazarotene gel ADR’s
-teratogenic effects on pregnancy
Methotrexate drug class and function
Immunosuppressent, cytotoxic agent that targets tissues with high growth rate, only should be used when severe psoriasis has not responded to safer therapy
Methotrexate ADR’s
- systemic administration can result in toxic effects
- GI effects
- bone marrow suppression
Acitretin (soriatane) drug class and function
Systemic retinoid agent for severe psoriasis
Acitretin (soriatane) ADR’s (3)
- hair loss
- dry skin
- damaged liver cirrhosis
Treatment of psoriasis with glucocorticoids
Effective but rarely used because it is worsened when discontinued
Cyclosporine drug class and function
Immunosuppressant that can treat moderate to severe psoriasis
Tumor necrosis factor antagonsists function
Inhibition of TNF suppresses immune function reducing inflammation in psoriais, very effective but can increase risk of opportunistic infections
Interleukin 12/23 antagonists function
Human monoclonal antibody directed againast interleukins 12 and 23 that promte inflammatory response, to decrease psoriasis
Phototherapy
Use of UV light for widespread disease or when psoriasis is unresponsive to topical agents, UVB is narrow band and safer and more effective
Phototherapy ADR’s (3)
- itching
- burning
- dryness
PUVA therapy
Use of long wave UVA radiation with methoxsalen (oxsoralen) a photosensitive drug, after absorbed UVA radiation causes methoxsalen to undergo rxn creating DNA psoralen complex decreasing proliferaiotn of epidermal cells
PUVA therapy ADR’s (3)
- pruritis
- increased risk of skin cancer
- erythema
Ketoconazole function
Antifungal cream and shampoo for seborrheic dermatitis
Topical minoxidil (rogaine) function
Used in a solution to treat male pattern baldness and thinning of hair in women by increasing cutaneous blood flow via vasodilation
Finasteride (propecia) drug class and function
5-a reductase inhibitor, Indicated for treatment of hair loss of males, inhibits conversion of testosterrone to DHT causing decrease in DHT conc. in scalp
Flurouracil function
PO antineoplastic agent used for topical treatment of multiple actinic keratoses and superficial basal cell carcinoma thru interupting DNA and RNA synthesis
Fluorouracil ADR
-itching, burning rash
Glucocorticoids for topical eczema can cause these 3 things with high enough doses
- skin atrophy
- hypopigmentation
- systemic effects
Tacrolimus (protopic) oitnment drug class and function
Calcineurin inhibitor (immunosuppressent) used to treat severe atopic dermatitis by reducing local immune response
UVA vs UVB
UVA is 95% of terrestrial UV radiation and penetrates skin much more deeply causing most skin aging, UVB is 5% and main cause of tanning and sunburn
Organic (chemical) sunscreens vs inorganic (physical) sunscreens
Organic absorb UV radiation and dissapate the heat, can cause contact dermatitis and photosensitivity rxns, inorganic reflect light (such as zinc oxide) by forming physicalbarriers
SPF to sunburn protection relationship
As SPF increases, protection increment becomes smaller, with values greater than 30 providing minimal benefit and products not being allowed to be labeled above 50 (just called 50+)
Mupirocin (bactroban) function
Inhibitor of protein synthesis and thus bactericidal topical agent against MRSA often used to treat impetigo or intranasal use for elimination of nasal carriage of S aureus
2 topical therapy choices for rosacea
- metronidazole
- azelaic acid
2 DOCs for scabies and pediculosis (lice)
permethrin and malathion
Lindane function
Absorbed thru the chitin shell laye of adult mites and lice causing death by inducing convulsions, eltahl to all eggs
Lindane ADR’s (2)
-irritation
convulsions if penetrates intact skin too much
Permethrin function
Agent of choice for mites and lice, toxic to them and their ova killing them by causing paralysis with minimal side effects
Malathion function
Agent of choice for mites and lice, has enzyme that kills lice and ova as an insecticide, devoid of significant ADR’s
