Skin Therapeutics/Topicals Flashcards
Advantages of topical treatments?
Direct application
Reduced systemic effects
Disadvantages of topical treatments?
Time-consuming
Correct dosage can be difficult
Messiness
Different bases/vehicles that drugs are dissolved in?
Gels Creams Ointments Pastes Lotions
What are creams and what do they contain?
Semi-solid emulsions of water that contain emulsifier and preservative
They have a high water content
Advantages of creams?
Cooling and moisturise
Non-greasy
Easy to apply
Cosmetically acceptable
What are ointments and what do they contain?
Semi-solid grease/oil (soft paraffin)
NO PRESERVATIVE
Advantages of ointments?
Occlusive and emollient
Restrict trans-epidermal water loss
Greasy - less cosmetically attractive
What are lotions and their main uses?
Liquid formulations that are suspensions/solutions of medication in water, alcohol or other liquids
Treatment of the scalp and hair-bearing areas
What are gels and their main uses?
Thickened aqueous solutions; they are semi-solids that contain high molecular weight solids
They can be used to treat the scalp, hair-bearing areas and the face
What are pastes and their main uses?
Semi-solids that contain finely powdered material, e.g: ZNO
They are often used in cooling, drying and soothing bandages
What are the advantages of pastes?
Protective, occlusive and hydrating
What are the disadvantages of pastes?
Stiff, greasy and difficult to apply
What are the TYPES of topical therapies (not the base/vehicle)?
Emollients Topical steroids Anti-infective agents (antiseptics, antibiotics, antivirals, antifungals) Anti-pruritics Keratolytics Psoriasis therapies
Functions and uses of emollients?
Enhance rehydration of the epidermis and are used for all dry/scaly conditions, esp. eczema; they can also be used as soap substitutes
Prescribing emollients?
Prescribe 300-500g weekly; these require frequent application
Difference between non-proprietary and proprietary emollients?
Non-proprietary (no trade name), e.g: soft paraffin, emulsifying ointment - these are cheaper
Proprietary (trademark name) - more expensive but more cosmetically acceptable (COMPLIANCE is higher)
When is wet wrap therapy used?
Used for very dry (xerotic) skin, however they are difficult and time-consuming to apply
3 modes of action of corticosteroids?
Vasoconstrictive
Anti-inflammatory
Anti-proliferative
Examples of topical steroids progressing from: Mild Moderate Potent Very potent ?
Mild - hydrocortisone (1%)
Moderate - Modrasone, Clobetasone, Butyrate (0.05%)
Potent - mometasone, betamethasone, Valerate (0.1%)
Very potent - Clobetasol, Proprionate (0.05%)
From mild to very potent, there is increasing anti-inflammatory and immunosuppressant effect
Conditions where topical corticosteroids are used?
Eczema (dermatitis)
Psoriasis
Other non-infective inflammatory dermatoses, e.g: lichen planus
Keloid scars (usually intralesional)
How to roughly estimate the topical steroid amount to apply?
1 application to the whole body of an adult should be 20-30g
1 fingertip unit = 1/2g
Thus, the correct amount should cover 2 hand areas
Side effects of topical steroids?
Thinning of the skin, purpura and stretch marks
Steroid rosacea
Fixed telangectasia
Perioral dermatitis
May worsen/mask infections
SYSTEMIC ABSORPTION
Tachyphylaxis (decrease in response to anti-inflammatory effects)
Rebound flare of disease, esp. in psoriasis
Examples of antiseptics applied topically?
Povidone iodine
Chlorhexidine
Hydrogen peroxide
Clinical uses of antiseptics?
Recurrent infections
Antibiotic resistance
Wound irrigation
What topical antibiotics are used for acne?
Clindamycin
Erythromycin, tetracycline
What topical antibiotics are used for rosacea?
Metronidazole
What topical antibiotics are used for impetigo?
Mupirocin, fusidic acid
What topical antibiotics are used for inffected eczema?
Combined corticosteroid/antibiotic (short-term)
How is herpes simplex (cold sore) treated?
Topical antiviral
How are eczema herpeticum and herpes zoster treated (shingles) treated?
Oral antiviral
How is candida (thrush) treated?
Anti-yeast, e.g: clotrimazole
How is dermatophytes (ringworm) treated?
Antidungal, e.g: clotrimazole
How is pityriasis versicolor treater?
Ketoconazole
Examples of anti-pruritics?
Menthol
Capsaicin
Camphor/phenol
Crotamiton
Function of keratolytics?
Used to soften keratin, e.g: in: Viral warts Hyperkeratotic eczema and psoriasis Corns and calluses To remove keratin plaques on the scalp
Example of a keratolytic?
Salicylic acid
How to treat warts?
MECHANICAL PAIRING plus: Keratolytics, e.g: Salicylic acid Formaldehyde Glutaraldehyde Silver nitrate Cryotherapy (usually liquid nitrogen) Podophyllin (genital warts)
Treatment of topical psoriasis?
EMOLLIENTS and a choice of:
Coal tar - messy and smelly
Vitamin D analogue - clean with no smell and easy to apply, but can be an irritant
Keratolytic
Topical steroid
Dithranol - effective but difficult to use; it is an irritant and stains normal skin
Scalp psoriasis treatment?
Greasy ointments to soften scale
Tar shampoo
Steroids in alcohol base or shampoo
Vitamin D analogues
What is Imiquimod used for?
Licensed for genital warts and superficial BCC; also, in solar keratoses, lentigo maligna, Bowen’s disease and verrucae
Function of Imiquimod?
Imidazoquinoline amine; it is an immune response modulator that enhances innate and cell-mediated immunity
It has anti-viral and anti-tumour effects
What are Calicneurin inhibitors?
Suppress lymphocyte activation and are used in the topical treatment of atopic eczema, esp. on the face and in children
There is no cutaneous atrophy but they may cause a burning sensation on application; there may be a risk of cutaneous infections and of skin cancer
Other topicals?
Sunscreens
Cosmetic camouflage
Side effects of topical therapies?
Burning/irritation
Contact allergic dermatitis
Local toxicity
Systemic toxicity
