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

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

Drugs To Be Discussed1 Antifungals: Griseofulvin Terbinafin Fluconazole Itraconazole Ketoconazole Corticosteroids: Topical Systemic Chloroquine

Drugs To Be Discussed2 Retinoids: Topical Systemic Benzoyl peroxide Shampoos Barriers Antibiotics: Topical Antivirals: Acyclovir Podophyllin Antiscabies: Benzoyl benzoate

Drugs To Be Discussed3 Antihistamines Anti-androgens Imiquimod

Antifungals Griseofulvin Terbinafin Fluconazole Itraconazole Ketoconazole

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

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

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

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

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

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

Corticosteroids Topical Systemic

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

Topical Corticosteroids Ointments: More potent Penetrates deeper More atrophy Used for: Dry lesions Thick lesions Thick skin

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

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

Topical Corticosteroids Shampoos Clobetasol: Used for psoriasis of the scalp

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

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

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

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

Benzoyl peroxide Comedolytic, antiseptic Gel / Cream Superficial, inflammatory acne vulgaris

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

Barriers Zinc/Castor oil BP: Nappy rash

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

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

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)

Penicillins Cloxacillin, Flucloxacillin, Amoxycillin-Clavulanic acid: Staph infections Amoxycillin, erythromycin: Strep infections

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

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

Antihistamines Sedating: Promethazine Chlorpheniramine Hydroxyzine (Aterax®)

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

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

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

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

Imiquimod (Aldara®) Topical immunostimulant Used for condylomata acuminata Superficial spreading basal cell CA Side-effects: Severe local inflammation