Dermatology Flashcards
What is the primary route for administering drugs for skin diseases?
Topical administration
What are the three layers of human skin?
Epidermis, Dermis, Subcutaneous layer (Hypodermis)
Name a major variable that determines pharmacologic response to drugs applied to the skin.
Regional variation in drug penetration
How does the concentration gradient affect drug transfer in the skin?
Increasing concentration gradient increases mass of drug transferred per unit time
What is the significance of the dosing schedule in dermatologic therapy?
The skin acts as a reservoir for many drugs, allowing for less frequent applications
What role do vehicles play in topical medications?
Vehicles facilitate cutaneous application and enhance drug penetration
List some types of dermatologic formulations based on the vehicle.
- Tinctures
- Wet dressings
- Lotions
- Gels
- Aerosols
- Powders
- Pastes
- Creams
- Foams
- Ointments
What is the best treatment for acute inflammation with oozing?
Drying preparations such as tinctures, wet dressings, and lotions
What is the best treatment for chronic inflammation with xerosis?
Lubricating preparations such as creams and ointments
What is the primary use of topical antibacterial agents?
Preventing infections in clean wounds and managing acne vulgaris
What are antibiotic-corticosteroid combinations used for?
Treating diaper dermatitis, otitis externa, and impetiginized eczema
What type of bacteria is bacitracin effective against?
Gram-positive organisms such as streptococci and staphylococci
What is mupirocin used for?
Eliminating nasal carriage of S aureus and treating skin infections
What type of organisms is polymyxin B effective against?
Gram-negative organisms including Pseudomonas aeruginosa and Escherichia coli
Which topical antibiotic shows greater activity against Pseudomonas aeruginosa?
Gentamicin
What is the mechanism of action of clindamycin in acne therapy?
In vitro activity against Propionibacterium acnes
What is the mechanism of action of erythromycin in inflammatory acne vulgaris?
Presumed inhibitory effects on P acnes
What is metronidazole used to treat?
Acne rosacea
What is the mechanism of action of sodium sulfacetamide?
Inhibition of P acnes by competitive inhibition of p-aminobenzoic acid utilization
Name some topical antifungal agents.
- Clotrimazole
- Miconazole
- Econazole
- Ketoconazole
- Oxiconazole
- Sulconazole
- Sertaconazole
- Ciclopirox olamine
- Naftifine
- Terbinafine
- Butenafine
- Tolnaftate
What is the action of ciclopirox olamine?
Inhibitory activity against dermatophytes and candida species
What enzyme do allylamines like naftifine and terbinafine inhibit?
Squalene epoxidase
What are nystatin and amphotericin B used for?
Topical therapy of C albicans infections
What is the mechanism of action of imiquimod?
Stimulates peripheral mononuclear cells to release interferon-Ɣ and interleukins
What are tacrolimus and pimecrolimus used for?
Treatment of atopic dermatitis
What is the typical formulation of sulfur for scabicide use?
5% precipitated sulfur in petrolatum
What type of agent is malathion?
Organophosphate cholinesterase inhibitor
Fill in the blank: Topical preparations of erythromycin use the _______ rather than a salt.
base
True or False: Acyclovir is effective against herpes simplex virus.
True
What is the usual formulation of precipitated sulfur used as a scabicide?
5% precipitated sulfur in petrolatum
What type of drug is Malathion?
Organophosphate cholinesterase inhibitor
How is Malathion applied for treating pediculosis?
0.5% lotion on dry hair; combed out after 4–6 hours
What are Hydroquinone, Monobenzone, and Mequinol used for?
Reduce hyperpigmentation of the skin
Which agent causes irreversible depigmentation?
Monobenzone
What is the mechanism of action for Hydroquinone and Mequinol?
Inhibition of the enzyme tyrosinase
What are Trioxsalen and Methoxsalen used for?
Repigmentation of depigmented macules of vitiligo
What is required for psoralens to produce a beneficial effect?
Photoactivation by long-wavelength ultraviolet light (UVA)
What are the major long-term risks of psoralen photochemotherapy?
Cataracts and skin cancer
What are the two types of compounds in topical medications for sun protection?
Sunscreens and sunshades
What does SPF stand for?
Sun Protection Factor
What is Retinoic Acid?
The acid form of vitamin A used for acne vulgaris
What is the effect of Retinoic Acid on epidermal cell turnover?
Increased turnover leading to expulsion of comedones
What is Adapalene?
A derivative of naphthoic acid applied as a 0.1% gel
What is the primary use of Isotretinoin?
Oral treatment of severe cystic acne
What is a significant risk associated with Isotretinoin?
Teratogenicity
What is the mechanism of action of Benzoyl Peroxide in acne treatment?
Antimicrobial activity against Propionibacterium acnes
What is Azelaic Acid effective for?
Treatment of acne vulgaris and acne rosacea
What is the mechanism of action of Salicylic Acid?
Keratolytic agent that solubilizes cell surface proteins
What is the concentration range of Salicylic Acid for keratolytic effects?
3–6%
What is the role of Propylene Glycol in dermatologic therapy?
Excellent vehicle and keratolytic agent
What is Urea’s effect on the stratum corneum?
Softening and moisturizing effect
What is the keratolytic concentration of Urea for treating ichthyosis?
0.2
What is the recommended concentration of Urea for softening nails?
30–50%
True or False: Doxepin is used for treating pruritus in atopic dermatitis.
True
What is the concentration of Pramoxine that can provide relief from pruritus?
0.01
