Derm Flashcards
1
Q
Absorption Considerations
A
- May need higher concentrations to yield benefit on thickest parts of skin
- Resistance can be overcome by higher concentrations
- More permeable places: face, axilla, groin
- Caution with abnormal or damaged stratum corneum
- Barrier function is compromised
- Increased absorption leads to toxicity (systemic absorption)
- Children have greater ratio of surface area to mass
- Same topical drug amount leads to greater systemic effects
- Vehicles and occlusion
- Vehicles maximize a drugs penetration
- Placing an occlusive dressing may enhance efficacy
2
Q
Types of Topical Drugs
A
3
Q
Topical Antibacterial Agents
A
- Indication: Prevent infections or early treatment of skin infections
- Most common organisms – β hemolytic streptococci and/or staphylococci
- Reducing staphylococci colonization in the nares
- Bacitracin, mupirocin, polymyxin B, neomycin
4
Q
Antifungal Agents
A
Tine corporis, pedis, cruris, unguium
- 1st line: terbinafine
- 2nd line: oral azole antifungal
- less fx: topical azole
Tinea capitis
- 1st line: griseofluvin
- altern: oral azole
Candida infections (localized candidiasis/diaper dermatitis)
- nystatin, topical azole
- combo: antifungal + zinc oxide + white petrolatum
5
Q
Griseofulvin
A
Susceptibility
- Dermatophyte infections; drug of choice for tinea capitis in children
Oral micronized & ultramicronized tablets
- Ultramicronized: Use 1⁄2 dose of micronized
- Give with fatty meal to increase absorption
Side Effects
- Common: Headaches, N/V/D, rash
- Rare: leukopenia, increase in LFTs
- Drug Interactions: CYP Inducer
- Derived from penicillin mold
6
Q
Antiviral Agents
A
Topical agents: acyclovir, penciclovir
Indications: HSV 1 & 2, herpes labialis (cold cores)
Side effects: pruritus, mild pain, stinging/burning sensation
7
Q
Ectoparasiticides
A
- Pediculus humanus corporis (body lice)
- Phthirus pubis (pubic lice)
- Sarcoptes scabiei - scabies
-
Pediculus humanus capitis (head lice)
- Pyrethroids (first line) aka “Rid” or “Nix”
- Spinosad (>4yo)
- Benzyl alcohol (>6mo)
- Ivermectin (>6mo)
- Malathion (>2yo) (last line)
- Lindane (do not use, neuro and hepatotoxic)
8
Q
Topical Corticosteroids
A
Immunosuppressive/anti-inflammatory
- Selection based on potency, site, severity of skin disease
- Nonfluorinated glucocorticoids (hydrocortisone, prednisone) can be used on face or occluded areas (axillae or groin)
Topical Absorption
- Minimal systemic absorption/effects
- Increased with occlusive dressing or skin is inflamed
- Increasing the concentration increases absorption
Cutaneous SE: purpura, striae, focal hypertrichosis, and acneiform or rosacea-like eruptions
- Skin atrophy with higher-potency agents, occlusion, use on thinner skin
- SE resolve after discontinuing use, but may take months
Potency:
-
Low potency – for infants
- Hydrocortisone butyrate 0.1% cream
-
Low-medium potency
- Thin, acute, inflammatory skin lesions
- Fluticasone propionate 0.05% cream
-
High-very high potency
- Chronic conditions, palms and soles of feet
- Generally do not use more than 2-3 weeks
- Betamethasone dipropionate 0.05% ointment
- Clobetasol propionate 0.05% lotion, cream
- Chronic conditions, palms and soles of feet
9
Q
Atopic Dermatitis
A
- Topical corticosteroids recommended if fail to respond to good skin care and regular use of emollients alone
- BID application generally recommended, however, evidence suggests once-daily some corticosteroids may be sufficient
- Proactive, intermittent use of topical corticosteroids as maintenance therapy (1-2 times/wk) on areas that commonly flare is recommended to help prevent relapses and is more effective than use of emollients alone
- Potential for both topical and systemic side effects, including possible hypothalamic-pituitary-adrenal axis suppression, should be considered with high potency
Drugs:
-
Topical calcineurin inhibitors (Immunosuppressive)
- Tacrolimus 0.03% ointment and pimecrolimus cream indicated for use in individuals age 2yo+
- Evidence from clinical trials supports safe & effective use in children < 2 years, including infants
- Tacrolimus 0.1% strength only approved in 15yo+
Indications
- Proactive, intermittent use as maintenance therapy (2-3 times per week) on areas that commonly flare to help prevent relapses while reducing need for topical corticosteroids
- For actively affected areas as a steroid-sparing agent
- Concomitant use with a topical corticosteroid may be recommended
10
Q
Topical calcineurin inhibitors (Immunosuppressive, atopic dermatitis)
A
Side Effects:
- Skin burning, pruritus, especially when applied to acutely inflamed skin
- Initial treatment with topical corticosteroids should be considered to minimize application site reactions
- Rare cases of malignancy (skin cancer/lymphoma) have been reported although causal relationship not established
- BBW added based on theoretical risk from the use of high-dose oral calcineurin inhibitor therapy in patients post- transplantation and from animal studies
- Avoid continuous long-term use and limit application to areas of involvement
11
Q
Acne: topical therapies
A
- <em>Propionibacterium acnes</em> (<em>P. acne</em>) is a part of normal skin flora that proliferates in a limited O2 and lipid rich environment
- Free fatty acids are generated causing irritating inflammatory lesions
Topical Therapies
-
Benzoyl peroxide
- Effective as monotherapy for mild acne
- Combination with a topical retinoid for moderate to severe acne
- Effective in prevention of bacterial resistance and is recommended for patients on topical or systemic antibiotic therapy
-
Topical antibiotics (e.g., erythromycin and clindamycin)
- Not recommended as monotherapy due risk of bacterial resistance
-
Topical retinoids
- Monotherapy in primarily comedonal acne
- Combination with topical or oral antimicrobials in patients with mixed or primarily inflammatory acne lesions
- Topical adapalene, tretinoin and benzoyl peroxide can be safely used in the management of preadolescent acne in children
12
Q
Antibiotics for acne
A
Clindamycin
- Combination products:
- +benzoyl peroxide (BenzaClin)
- +tretinoin (Ziana)
- Water based gel & lotions are well tolerated
- Foam formulation causes drying, irritation, and burning
- May cause photosensitivity (use sunscreen)
Erythromycin
- Combination products:
- +benzoyl peroxide (Benzamycin)
- Water based gel is well tolerated
- Solution causes drying, irritation and burning
- Higher incidence of resistance
Benzoyl Peroxide
Various combinations
- Irritation (start with low [] and titrate)
13
Q
Topical retinoids for acne
A
Natural compounds that exhibit vitamin A activity
- MOA: Correct abnormal follicular keratinization, reduce P. acne, reduce inflammation
- Topical concerns: Photosensitivity reaction (increase risk of sunburn)
-
Tretinoin (Retin-A-Micro)
- Erythema and dryness
- Do not use with benzoyl peroxide (inactivation)
-
Adapalene (Differin)
- Less irritating than tretinoin
- Okay with benzoyl peroxide
- Stable in sunlight
-
Tazarotene (Tazorac) third gen retinoid
- Burning/stinging
- Minimize sun exposure
- Contraindicated in pregnancy** Only topical product to have this warning
14
Q
Oral isotretinoin (Accutane, Absorica, Claravis, Myorisan, Zenatane, Amnesteem)
A
- Treatment for:
- Severe nodular acne
- Moderate acne that is treatment-resistant
- Mgmt of acne that is producing physical scarring and/or psychosocial distress
- Low-dose isotretinoin can be used to effectively treat acne and reduce the frequency and severity of medication-related side effects
- Intermittent dosing not recommended
- Side Effects:
- Common: dryness, itching, lipid abnormalities
- Less Common: Headache, anorexia, alopecia, muscle & joint pain
- iPLEDGE risk management program
- Contraindicated in pregnancy
- Must use effective contraception & have negative pregnancy test for 1 month after treatment
- Routine monitoring of LFTs, serum cholesterol and TG at baseline and again until response to treatment is established
- Monitor and counsel for depressive symptoms
15
Q
Oral antibiotics for acne
A
- Management of moderate and severe acne; forms of inflammatory acne that are resistant to topical treatments
- Combination therapy only with topical therapy
- Benzoyl peroxide and/or a retinoid
- First Line: Doxycycline and minocycline
-
Second Line (restricted to those unable to tolerate first line):
- Erythromycin and azithromycin
- Restrict erythromycin due to increased risk of resistance
- Trimethoprim-sulfamethoxazole and trimethoprim
- For treatment resistant patients
- Erythromycin and azithromycin
- Limited to shortest possible duration
- ~3 months to minimize development of resistance
