Pharm -Mata Flashcards
Which medication vehicles are best for hairy areas?
Lotions and solutions
Where should you avoid using ointments? What type of medication vehicle should be used in these regions?
intertriginous (skin contacts skin–> armpit, groin, pannus)
Use creams instead
What are the components of writing a topical prescription? (6)
- Generic name
- Vehicle
- Concentraion
- Sig (signa=”write on label” =BID, PRN, etc)
- Amount
- Refills
Example: Desonide cream 0.05% apply to affected area (face) BID PRN for scaling #15 grams RF 3
How do corticosteroids work (3 mechanisms)?
- activate genes encoding beta2 adrenergic receptors and anti-inflammatory proteins
- inhibit transcription factors like NF-kB and AP-1
- Modulate signal transduction pathways through interaction between the T cell receptor and interference with the JNK signal
What determines the efficacy of topical medications?
strength (potency), location, vehicle and concentrations
What are some local side effects of topical steroid use? How are these affected by the potency?
- skin atrophy
- Telangiectasias
- Striae
-higher potency==> more likely SE
What are some systemic SE of topical steroids?
- Glaucoma
- hypothalamic pituitary axis suppression
- Cushing’s syndrome
- HTN
- Hyperglycemia
How long should you use super high potency corticosteroids to limit SE? High and medium potency?
super high = < 3 weeks
high and medium= <6-8 weeks
What percentage BSA is the size of your palm?
1%
if measuring on a pt, use their hand, not yours
What is 1 fingertip unit in mg? How much BSA can this cover?
1 Fingertip unit (FTU)= 500 mg = treats 2% BSA
How many grams should be given to cover 2 palms of area (2% BSA), 2 times per day for 1 month?
30 grams
Why do kids have a higher risk for systemic absorption of topically applied meds than adults?
they have a higher SA: body ratio
What 4 processes have a role in the formation of acne lesions?
- inflammatory mediators released into skin (PLC/ PKC inducing IL-1 and other inflammatory reactions)
- alteration of keratinization –> comedones
- increased and altered sebum production (under androgen control) (PI3K/Akt and Shh/MC5R pathway inducing terminal sebocyte differentiation)
- follicular colonization by P. andes
What are topical antibiotics be given with for the treatment of inflammatory papules and pustules? Why?
- Benzoyl peroxide
- prevent the development of antibiotic resistance
How does Benzoyl peroxide work?
-antibacterial: form highly reactive ROS that oxidize bacterial cell membranes (and yeasts)
What do topical retinoids target? What should they not be given with?
- comedones
- should not be given with benzoyl peroxide because benzoyl peroxide will oxidize it
How long does it take topical acne treatment to take effect?
2-3 months
patient education is crucial
What are the side effects of oral tetracyclines? How do these affect birth control pills?
GI upset and photosensitivity (except Minocycline)
Minocycline=vertigo and hyperpigmentation
- take with water to avoid esophageal erosions
- do NOT interfere with birth control
What is oral Isotretinoin used to treat? What are some side effects?
- used to treat severe nodulocystic scarring acne or acne resistant to other therapies
- TERATOGENIC –> contraindicated in pregnant and MUST use 2 forms of contraception
- Xerosis (dry skin)
- Cheilitis (chapped lips)
- Elevated liver enzymes
- hyper triglyceridemia
- severe acne sufferers might suffer mood changes –> monitor for depression
- Pseudotumor cerebri (–> HA from inc ICP)
Which class of antihistamines are better for anti-histaminic properties?
- 2nd generation (Cetirizine, Loratadine, fexofenadine)
- 1st generation work through sedative functions (Diphenhydramine, Hydroxyzine and Chlorpheniramine)
Why are topical vitamin D analogs used for treatment of Psoriasis?
-Calcipotriene inhibits keratinocyte proliferation
(SE=skin irritation)
-Calcitriol also inhibits keratinocyte proliferation, inhibits T cell proliferation and stimulates keratinocyte differentiation (less skin irritation)
What effect does Tar have on psoriasis? What can it be combined with?
anti proliferative effect
can combine with salicylic acid to penetrate thick plaques
What is a SE of Tazarotene? What can be given with it to reduce this SE ?
- it is a topical retinoid used for acne, rosacea and psoriasis
- SE=skin irritation
- give with a class II corticosteroid to dec irritation
How many grams does it take to cover an average adult body (1 application)?
30 grams*
