topical drugs, antihistamines Flashcards
what layer of skin does most cell division occur?
basal layer
which layer of the epidermis is the major barrier to percutaneous absorption?
stratum corneum
what are the pathways of absorption into the skin?
- shunt route
- transcellular route
- intercellular route
what is the most common route of absorption for the small uncharged molecules thru the skin?
intercellular route
what sort of solns to use on scalp/other hairy areas?
lotions, gels, soln, foam, aerosol
what sort of solns to use on areas where skin rubs against itself?
creams, lotions, solns
what is the partition coefficient?
partitioning of drug from vehicle into stratum corneum
what is the drug diffusion coefficient?
molecular aspects of the drug allowing diffusion across the skin layers
derivative of coal tar, used to tx inflammatory & noinflamm acne, use does not lead to resistance
benzoyl peroxide
what drug do you never see combined with tretinoin?
benzoyl peroxide
MOA: induces apoptosis sebum producing cells of sebaceous glands–>directly suppresses sebum production
isotretinoin
which retinoid? teratogenic (women must be on effective contraception 1 month prior, during and for 1 or more menstrual cycles following tx
isotretinoin
which drugs fxn by normalizing follicular keratinization?
retinoids, salicyclic acid, azelaic acid, benzoyl peroxide
which retinoid is admin with alcohol to prolong elimination time?
acitretin
what is tachyphylaxis?
diminshed therapeutic benefit
how to prevent tachyphylaxis?
use alternate day application
what is the triple response of lewis?
- red spot
- flare
- wheal
where are there greater numbers of mast cells?
bronchial mucosa, intestinal mucosa, skin
which type of histamine release results from membrane damage?
cytolytic histamine release
which type of histamine release requires prior sensitization?
noncytolytic histamine release
which Histamine receptor: expressed in smooth muscle cells, vascular endothelial cells, CNS neurons, peripheral sensory neurons
H1
which Histamine receptor: gastric parietal cells, cardiac muscle, CNS neurons
H2
which histamine receptor induces Ca release in the cells (Gq)?
H1
which histamine receptor stimulates Gs?
H2
activation of the____receptors in peripheral neurons of the epidermis causes itch, and of the dermis cause pain
H1
activation of the _____receptors in the lung smooth muscle cells–>bronchoconstriction?
H1
activation of the ____receptors in cardiac muscle–>incr contractile force, incr HR
H2
which diseases cause incr in histamine levels?
- myelogenous leukemia
- gastric carcinoid tumors
- systemic mast cell diseases
what is an inverse agonist?
H1 antihistamines irreversibly bind to receptor & stabilize the inactive form
which 1st generation has a significant inhibition of A1 adrenergic receptors?
promethazine
which H1 antihistamines have the strongest antiemetic effects
diphenhydamine, promethazine, hydroxyzine, meclazine
which H1 antihistamines have the highest sedative effects?
diphenhydamine, promethazine, hydroxyzine
which H1 antihistamines have the highest anticholingeric effects?
diphenhydamine, promethazine
which H1 antihistamine has anti-serotonin receptor effects?
cyproheptadine
azelastine can be administered ______ and ______
intranasal and opthalamic
of the 2nd generation H1 antihistamines, which ones have a potential for slight drowsiness?
levocetririzine, cetirizine
MOA: Stabilize mast cells (inhib degranulation) via inhib of chloride channels
Cromolyn & Nedocromil
MOA: Recombinant humanized monoclonal ab that binds IgE–>prevents Ab from binding mast cells
Omalizumab
what to use for severe psoriasis?
acitretin
