Dermatopharmacology

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Dermatopharmacology

• Prof Werner Sinclair
• Department of Dermatology
• University of the Free State

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Outcomes for this Lecture

• After this lecture the student should be able to
•  
• Name the most important characteristics and uses
  of the following antifungals
• Griseofulvin
• Terbinafine
• Ketoconazole
• Fluconazole
• Itraconazole
• Topical imidazole creams
• Discuss the characteristics and uses of the
  different strengths and formulations of topical
  steroids
• Name the indications for and most important
  side-effects of chloroquine
• Discuss the indications and use of topical
  retinoids
• Discuss the origin, characteristics of and
  indications for mupirocin
• Discuss the use of tetracyclines in dermatology
• Name the uses of the different types of
  antihistamines (sedating vs non-sedating) in
  dermatology
• Name the indications for and side-effects of
  anti-androgens and imiquimod

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Drugs To Be Discussed1

• Antifungals Griseofulvin
• Terbinafin
• Fluconazole
• Itraconazole
• Ketoconazole
• Corticosteroids Topical
• Systemic
• Chloroquine

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Drugs To Be Discussed2

• Retinoids Topical
• Systemic
• Benzoyl peroxide
• Shampoos
• Barriers
• Antibiotics Topical
• Systemic
• Antivirals Acyclovir
• Podophyllin
• Antiscabies Benzoyl benzoate

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Drugs To Be Discussed3

• Antihistamines
• Anti-androgens
• Imiquimod

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Antifungals

• Griseofulvin
• Terbinafin
• Fluconazole
• Itraconazole
• Ketoconazole

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Griseofulvin

• Only active against dermatophytes (keratolytic
  fungi)
• Fungistatic
• Absorbed with fatty food (milk)
• Very safe in children
• 10 20 mg per kg per day

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Terbinafin

• Only active against dermatophytes
• Fungicidal
• Tablets and cream
• Some severe immunological side-effects

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Fluconazole

• Broad spectrum
• Fungistatic
• Convenient once per week dosage
• Can be used in neonates
• Used for Candida
• Cryptococcus

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Itraconazole

• Very broad spectrum
• Fungistatic
• To be taken with meals
• Capsules and suspension available
• Used for Any fungal infection
• Not better than terbinafin for
• 
  dermatophytes

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Ketoconazole

• Broad spectrum
• Fungistatic
• To be taken with meals
• Tablets, cream and shampoo available
• Used for Seborrheic dermatitis
• Pityriasis versicolor
• Candidiasis
• Side-effects Liver toxicity
• P450 inducer

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Imidazole Creams

• Variety available
• Similar spectra
• Little to choose
• Price deciding factor
• E.g.. Ketoconazole, econazole, clotrimazole

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Corticosteroids

• Topical
• Systemic

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Topical Corticosteroids

• 3 Strengths
• Fluorinated vs Non-fluorinated
• Ointments, Creams, Lotions, Shampoos

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Topical Corticosteroids

• Ointments More potent
• Penetrates deeper
• More atrophy
• Used for Dry lesions
• Thick lesions
• Thick skin

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Topical Corticosteroids

• Creams Less potent
• Penetrates less
• Less atrophy
• Used for Acute, thin lesions
• Moist lesions
• Thin skin (Face, skin folds)

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Topical Corticosteroids

• Lotions Least potent, least atrophy
• Used for Hairy areas (scalp)
• Wet lesions (Watery solutions)

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Topical Corticosteroids

• Shampoos
• Clobetasol Used for psoriasis of the scalp

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Systemic Corticosteroids

• Prednisone / Prednisolone
• Potent, fast acting anti-inflammatory
• Cheap
• Side-effects Short term Almost none
• Long term Severe
• Used once daily, in the morning

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Chloroquine

• Indications Cutaneous lupus erythematosus
• Porphyria cutanea tarda
• Side-effects Corneal deposits (Temporary)
• Maculopathy (Permanent)
• Other

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Retinoids

• Topical Tretinoin
• Adapalene
• Tazarotene
• Comedolytic, anti-inflammatory
• Indications Acne (All forms)
• Anti-aging
• Other

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Retinoids

• Systemic Isotretinoin
• Acitretin
• Indications Acne
• Psoriasis
• Lymphomas
• Many others
• Side-effects, etc See acne lecture

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Benzoyl peroxide

• Comedolytic, antiseptic
• Gel / Cream
• Superficial, inflammatory acne vulgaris

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Shampoos

• Ketoconazole Seborrheic dermatitis
• Pityriasis versicolor
• (Not for tinea
  capitis)
• Coal tar (LPC) Psoriasis
• Povidone iodine (Betadine)
• Selenium sulfide (Selsun)
• Zinc pyrithione

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Barriers

• Zinc/Castor oil BP Nappy rash

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Antibiotics

• Topical Mupirocin
• Fucidic acid
• Gentamycin
• Erythromycin
• Clindamycin
• Systemic Tetracyclines (oxytetracycline,
  doxycycline, minocycline, lymecycline)
• Penicillins (amoxycillin,
  cloxacillin, amoxycillin-clavulanic acid
• Erythromycin

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Mupirocin

• Manufactured by Pseudomonas bacteria
• Broad spectrum
• Esp effective against Staphylococci
• Ointment and cream
• No systemic use
• Reserved for short term use

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Tetracyclines

• Bacteriostatic antibiotics, potent anti-
• 
  inflammatory effects
• Used widely in acne, rosacea, bullous diseases
• Oxytetracycline Rosacea
• Lymecycline Drug of choice for acne
• Minocycline Acne in white patients
  (pigmentation)
• Doxycycline Acne in black patients
  (phototoxicity)

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Penicillins

• Cloxacillin, Flucloxacillin, Amoxycillin-Clavulani
  c acid Staph infections
• Amoxycillin, erythromycin Strep infections

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Antivirals

• Acyclovir Cream, tablets and IV
• Used for Herpes simplex 1 and 2
• Herpes zoster
• (Cream useless on skin)
• Side-effects Practically none
• Podophyllin 25 in TBCo Used for condylomata
  acuminata and verrucae

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Antiscabies

• Benzoyl benzoate
• Only effective treatment for scabies
• Method of use See lecture on skin infections

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Antihistamines

• Sedating Promethazine
• Chlorpheniramine
• Hydroxyzine (Aterax)

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Antihistamines

• Sedating Promethasine
• Chlorpheniramine
• Hydroxyzine (Aterax)
• Used for Atopic dermatitis
• Acute urticaria
• Other forms of night-time
  pruritus

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Antihistamines

• Sedating Promethasine
• Chlorpheniramine
• Hydroxyzine (Aterax)
• Used for Atopic dermatitis
• Acute urticaria
• Other forms of night-time
  pruritus
• Side-effects Sedation (NB Driving)
• Photo-allergy (not
  hydroxyzine)
• Dry mouth

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Antihistamines

• Non-sedating Loratidine
• Cetirizine
• Desloratidine
• Levocetirizine
• Used for Acute and chronic urticaria
• Allergic rhinitis
• Side-effects Almost none

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Anti-androgens

• Cyproterone acetate
• Progestogen, blocks 5a-reductase
• 2mg in Diane-35
• 10mg in Androcur
• Used mostly for acne
• Side-effects Depression, weight gain
• Drosperinone
• Ingredient of Yasmin

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Imiquimod (Aldara)

• Topical immunostimulant
• Used for condylomata acuminata
• Superficial spreading basal
  cell CA
• Side-effects Severe local inflammation