Skin theraputics Flashcards
What is a cream?
A semisolid emulsion of water and oil
What do all creams contain?
Preservative and emulsifier
Have a high water content
What is an ointment?
Semisolid grease/oil (soft paraffin)
Do ointments contain a preservative?
No
What are the uses and advantages of ointments?
Occlusive and emollient
Restrict transepidermalwater loss
What is a lotion?
Suspension or solution of medication in water, alcohol or other liquids
Which areas are lotions used to treat?
Scalp and hair-bearing areas
What are gels and what do they consist of?
Thickened aqueous lotions
Semi-solids, containing high molecular weight polymers e.g. methylcellulose
What are pastes and what do they consist of?
Semisolids
Contain finely powdered material e.g. ZNO
What are the disadvantages of pastes?
Stiff
Greasy
Difficult to apply
What are the advantages of pastes?
Protective
Occlusive
Hydrating
Which kind of preparation is often used in bandages?
Pastes
What do emollients do?
Enhance rehydration of epidermis
How much emollient should be prescribed weekly?
250-500g
What are wet wraps used to treat?
Extremely dry skin
What is the disadvantage of wet wraps?
Time consuming to apply
What are the four main modes of action of topical steroids?
Vasoconstrictive
Anti-inflammatory
Anti-proliferative
Cause immune suppression
What is the most mild topical corticosteroid?
Hydrocortisone 1%
Which are moderate topical steroids?
Modrasone
Clobetasone butyrate 0.05%
Which are potent topical steroids?
Elocon
Betamethasone valerate 0.1%
Which is the most potent topical corticosteroid?
Clobetasol proprionate0.05%
Which conditions are topical steroids used in?
Eczema
Psoriasis
Other non-infective inflammatory dermatoses e.g. lichen planus
Keloid scars
What are the side effects of topical steroids on the skin?
Thinning skin Stretch marks Purpura Fixed telangectasia Perioral dermatitis Steroid rosacea
What are some examples of topical antiseptics?
Povidone iodine
Chlorhexidine
Triclosan
Hydrogen peroxide
Which situations are topical antiseptics used in?
Recurrent infections
Antibiotic resisistance
Wound irrigation
Which topical antibiotics are used for acne?
Clindamycin
Erythromycin
Tetracycline
Which topical antibiotics are used for impetigo?
Mupirocin
Fusidic acid
Which topical antibiotics are used for rosacea?
Metronidazole
What is the treatment for infected eczema?
Combination of steroid & antibiotics
Which condition is treated with a topical antiviral?
Herpes simplex
Which conditions are treated with oral antivirals?
Eczema herpeticum
Herpes zoster
What are some examples of antiprutitics?
Camphor
Crotamiton
Menthol
Capsaicin
What are some topical treatments for psoriasis?
Emollients Coal tar Vitamin D analogue Keratolytic Topical steroid Dithranol
What is imiquimod?
An immune response modulator
Enhances innate & cell-mediated immunity
What are the uses of imiquimod?
Genital warts Superficial BCC Solar keratoses Lentigo maligna Bowen’s disease Verrucae
Which layer of the skin is the most important barrier to drug penetration?
Stratum corneum/keratin layer
What does the ‘brick and mortar’ structure of the stratum corneum describe?
‘Bricks’ (Corneocytes, containing keratin filaments in a cornified cell envelope)
‘Mortar’ (lamellar structures of intercellular lipids, i.e. ceramides, cholesterol, free fatty acids)
Which two routes can drugs take across the stratum corneum?
Intercellular (around corneocytes)
Transcellular
What is the advantage of a high lipid content in a topical drug?
Works better for longer
What is the disadvantage of a high lipid content in a topical drug?
Messy and greasy
What is the subcutaneous route of drug administration?
Drug delivered by a needle (inserted into the fatty (adipose) tissue just beneath the surface of the skin)
Which drugs are best suited to transdermal patch administration?
Those that are potent, lipophilic and of relatively brief half life
