Flashcards in Topical Therapeutics in Dermatology Deck (19):
Which layer of the skin is described as having a "brick-and-mortar" appearance? What are the "bricks" and "mortars"?
The stratum corneum of the epidermis; corneocytes are the bricks and intercellular lipids are the mortar
The three ways drugs can pass through the skin are _______.
passive diffusion through tissue, seeping through pores in the brick-and-mortar network, and through apendageal structures
List the drug factors that affect absorption.
Lipophilicity, vehicle composition, size, and concentration
Ointments are _____.
water in oil emulsions
Creams are ______.
oil in water emulsions
Sites most amenable to gels are ______.
the oral mucosa and the scalp
The benefits of ointments are __________. The downsides are _____.
high potency, low sensitization risk, hydrating; greasy, not useful for intertriginous sites or face
A common unit of measurement for topicals is the ______.
fingertip unit (FTU), roughly 0.5 g; it is the amount the covers the distal phalange of the second digit with a 5 mm dispensing tube
Foams are aerosolized gel matrices. What are their benefits and downsides?
They dry fast and don't leave a residue, so they work well on hair-bearing areas.
While most areas of the body are amenable to creams, clinicians should avoid creams on _______.
macerated areas (sites that have been damaged due to excessive moisture)
One gram of cream covers _______.
roughly 10 cm^2 (ointment covers 10% more)
There are seven classes of topical corticosteroids. Name a class one (most potent), class seven (least potent), and one in between.
1 = clobetasol propionate, 7 = hydrocortisone, and 4 = triamcinolone acetonide
List the patient factors that affect drug absorption.
(1) anatomic location, (2) skin hydration, (3) presence of a barrier, and (4) occlusion
Gels are _________.
semisolid emulsifications in alcohol; great for the mucosal surfaces or the scalp (because gels dry quickly); not great for fissures or macerated areas
Foams have _______ potency.
strong (because the inactive volatile ingredients evaporate, leaving behind only the active ingredients)
List some FTUs for various body parts.
Trunk (front or back) 7 FTU; arm 3 FTU; leg 6 FTU; foot 2 FTU
How many grams of cream are needed to cover the entire body of an adult man?
Describe the mechanism of glucocorticoid action.
Glucocorticoids bind to cytosolic receptors, which then dimerize and act as a transcription factor for several anti-inflammatory genes. This ultimately leads to the down-regulation of GM-CSF, nF-KB, and several interleukins.