Dermatologic Pharmacology (Part 3) Flashcards
what is neuropathic localized pruritus?
without primary rash, due to compression or degeneration of nerves in the skin en route to the spine or in the spine itself
what are 5 nonpharmacologic interventions for pruritus?
skin moisturization, cool environment, avoidance of skin irritants, stress reduction, and physical interventions
what is calamine lotion?
mixture of zinc oxide and iron oxide, MOA is unclear but it cools
what is menthol and camphor?
it is useful in patients who report cooling as an alleviating factor
what is capsaicin?
particularly useful in neuropathic itch
how are topical corticosteroids (hydrocortisone) used for pruritus?
not directly antipruritic, but may be useful in pruritus due to inflammatory skin dermatoses
what is doxepin?
a topical antihistamine that is useful for histamine induced itching (like bug bites); avoid in children
what is pramoxine?
a local anesthetic found in a variety of OTC remedies; useful for pruritus on face and that associated with CKD
what is capsaiscin?
activates TRPV1 and is sensed as hot
what is menthol, camphor, and icilin?
activates TRPM8 and is sensed as cold
when using a topical steroid, how should you begin?
start with high potency to gain control and titrate downward for maintenance; use low potency on face, genitals, and skin folds
what do antihistamines block?
H1 receptors
what is salicylic acid?
a COX inhibitor known for its anti-inflammatory activities
what are the effects of salicylic acid?
causes epidermal cells to shed more readily, has antibacterial properties, and opens clogged pores; skin softening effects; applied in more concentrated solutions for calluses and warts; useful for treating thickened scaly skin associated with repeated itching/scratching (lichen simplex chronicus)
what can prolonged used of salicylic acid lead to?
salicylate toxicity, especially in children and those with reduced kidney function or liver function
what are two topical vasoconstrictors for rosacea?
brimonidine and oxymetazoline
what is brimonidine?
an alpha-2 adrenergic agonist applied as a topical gel
what is oxymetazoline?
a mixed alpha1/alpha2-adrenergic agonist applied as a topical cream
what are the vasoconstrictors used for the eyes?
naphazoline, tetrahydrozoline and phenylephrine
what are the drugs used to kill ectoparasites?
malathion, permethrin, ivermectin, and lindane
what is malathion?
a topical agent, organophosphate cholinesterase inhibitor
what is permethrin?
a topical agent, binds to insect Na+ channels and blocks membrane repolarization
what is ivermectin?
administered orally, binds to glutamate-gated Cl- channels in invertebrates, hyperpolarizes the nerve and muscle cells
what is lindane?
topical agent, toxicity causes to be used only after all other agents fail; disrupts GABAergic transmission in insects
