Dermatologic Pharmacology (Part 1)

Question 1

What are 4 variables that affect the rate of cutaneous absorption of products?

Answer 1

regional, concentration gradient, dosing schedule =, and vehicles/ occlusion (both can maximize drug penetration)

Question 2

what is the mixture of creams vs ointments?

Answer 2

creams are a mixture of half water and half oil with emulsifier and ointments are a mixture of about 20% water and 80% oil

Question 3

what are the emulsifiers used on creams?

Answer 3

cetyl alcohol

Question 4

what are the general characteristics of creams?

Answer 4

they spread easily (i.e. good for large areas), are well absorbed, and wash off with water; too thick to pump;

Question 5

when are creams better than ointments?

Answer 5

creams are better for oozing/ “wet” skin conditions

Question 6

what are the oil components that are in ointments?

Answer 6

hydrocarbons such as mineral oil or petroleum jelly

Question 7

what are the general characteristics of ointments?

Answer 7

they feel greasy and are “occlusive” meaning that they stay on the surface of the skin and are not well absorbed

Question 8

when are ointments better than creams?

Answer 8

best used on dry skin since they trap moisture; they provide for more complete absorption of the active ingredient or medication

Question 9

what is special to note about ointments and adverse effects?

Answer 9

they are less likely to cause an allergic reaction than creams, because creams contain preservatives

Question 10

how long should you wash your hands?

Answer 10

15-30 seconds

Question 11

alcohol-based hand disinfection is rapidly effective against what?

Answer 11

gram-positive, gram-negative, and viral pathogens; not effective against C. difficile

Question 12

what are the 3 components in moisturizer?

Answer 12

emollients, humectants, and horny substance softeners

Question 13

what are emollients?

Answer 13

they form an oily layer on top of the skin that traps water in the skin

Question 14

what are 4 examples of emollients?

Answer 14

petrolatum, lanolin, dimethicone, and mineral oil

Question 15

what are humectants?

Answer 15

they draw water into the outer layer of the skin

Question 16

what are 3 examples of humectants?

Answer 16

glycerin, lecithin, and propylene glycol

Question 17

what are horny substance softeners?

Answer 17

they loosen the bonds between the top stratum corneum layer of skin which helps the dead skin cells fall off, helps the skin retain water, and gives it a smoother, softer feeling in thicker areas

Question 18

what are 4 examples of horny substance softeners?

Answer 18

alpha hydroxyacids, salicylic acid, urea, and allantoin

Question 19

what type of moisturizer should be used on normal skin type?

Answer 19

water-based moisturizer that has a light non-greasy feel; these moisturizers often contain light weight oils

Question 20

what type of moisturizer should be used on dry skin?

Answer 20

choose a heavier, oil-based moisturizer

Question 21

what products are preferred for very dry cracked skin?

Answer 21

petrolatum-based products since they prevent water from evaporating

Question 22

what type of moisturizer should be used for oily skin?

Answer 22

water based product that is labeled “noncomedogenic”

Question 23

what moisturizer should be used for sensitive skin?

Answer 23

one with soothing ingredients such as chamomile or aloe that does not contain potential allergens (fragrances of dyes) or acids

Question 24

what moisturizer should be used for mature skin?

Answer 24

oil-based moisturizer that contains petrolatum as the base to keep skin hydrated plus antioxidants or alpha hydroxyacids to combat wrinkles

Question 25

what does UVB radiation cause?

Answer 25

erythema/sunburn and skin aging and photocarcinogensis

Question 26

what does UVA radiation cause?

Answer 26

skin aging and cancer

Question 27

what 2 active ingredients are used in sunscreen?

Answer 27

benzophenones and dibenzoylmethanes

Question 28

what was the classic active ingredient in sunscreen but is now not commonly used?

Answer 28

PABA- not used now due to hypersensitivity concerns

Question 29

what is an example of a benzophenon?

Answer 29

oxybenzone

Question 30

what is an example of dibenzoylmethane?

Answer 30

avobenzone

Question 31

what are dibenzoylmethanes particularly useful for?

Answer 31

conditions such as drug-induced photosensitivity and cutaneous lupus erythematous

Question 32

what are sunshades and what is an example?

Answer 32

opaque materials that reflect light; classic example is titanium dioxide

Question 33

what is chlorhexidine?

Answer 33

a broad-spectrum antimicrobial agent that is widely used in homes and hospitals due to safety, general efficacy on skin, and low irritability

Question 34

what is the general hierarchy to resistance to antiseptic and disinfectants?

Answer 34

prions–> protozoan (cryptosporidium oocysts)–> C. difficle spores

Question 35

what are 5 examples of antibiotic resistance mechanisms of biofilms?

Answer 35

they limit penetration, they have persistent cells, they neutralize antibiotics, they have enzymes that break down antibiotics, and they slow growth making them harder to kill