Dermatology - pharmacology and prescribing Flashcards
What are some institutions that approve use of medications in the UK?
Medicines and Healthcare products Regulatory Agency (MHRA).
European Medicines Agency (EMA)
Scottish Medicines Consortium (SMC)
What is meant by off label medications?
A licensed medication that is being used for an unlicensed indication.
What is meant by specials medications?
Unlicensed dermatological preparations e.g tar.
What is pharmacokinetics?
The effect of the body on the drug.
What is pharmacodynamics?
The effect of the drug on the body.
What are some key things to think about regarding pharmacokinetics?
Route of administration
Distribution
Metabolism - especially in liver disease
Excretion - especially in renal disease.
What are some key things to think about regarding pharmacodynamics?
Age of patient
Pregnancy
Drug interactions
Pharmacogenetics.
What are some factors associated with poor adherence?
Psychiatric co-morbidities Slower acting agents Multiple applications per day. Lack of patient education. Cosmetic acceptability of treatments. Unintentional non-adherence.
What is required for topical therapy?
Need a vehicle (pharmacologically inert, chemically and physically stable substance to carry an active drug) + and an active drug.
What are some factors the affect absorption?
Concentration Base Chemical properties of the drug. Thickness and hydration of stratum corneum. Temperature. Skin site Occlusion.
What are some examples of vehicles?
Solutions Cream Lotion Gel Foam Tape Paste Spray powder Shampoo Ointment Paint
What are some examples of drugs used topically?
Corticosteroid Antibiotics Antiviral Dithranol Vitamin analogues Chemotherapy Parasiticidals Coal tar Anti - inflammatories Salicyclic.
How do topical steroids work?
Anti-inflammatory and immunosuppressive properties : regulate pro inflammatory cytokines
Suppress fibroblast, endothelial and leukocyte function.
Vasoconstriction
Inhibit vascular permeability.
What are some side effects of topical steroids?
Thinning/atrophy Striae Bruising Hirsutism Telangiectasia Acne Rosacea Perioral dermatitis Glaucoma Systemic absorption Cataracts
What are the systemic treatments in dermatology?
Retinoids.
Traditional immunosuppressants.
Biologics.
What are the 4 oral retinoids used in Dermatology and what are they used to treat?
Isotretinoin - acne
Acitretin - psoriasis
Bexarotene - cutaneous T cell lymphoma
Alitretinoin - Hand eczema.
What are some side effects of retinoids?
Teratogenic Cheilitis (dry lips) Xerosis (dry skin) increased transaminases increased triglycerides
Can also have psychiatric, eye and bone side effects although these aren’t as common.
What are some examples of immunosuppressants?
Oral steroids Azathioprine Ciclosporin Methotrexate Mycophenolate mofetil
What are some side effects of immunosuppressants?
Malignancy
Serious infection
Need regular blood test monitoring: FBC ( esp in methotrexate and azathioprine) Renal function tests ( esp ciclosporin) Liver function tests ( esp methotrexate)
What does the suffix -cept indicate?
Receptor fusion - genetically engineered fusion protein. e.g Etanercept
What does the suffix -mab indicate?
Monoclonal antibodies
What do the following infixes mean; zu, ix, u, li/l?
zu - humanised
ix - chimeric
u - fully human
li/l - immunomodulator
What are some examples of licensed biologics in the UK?
Adamlimumab
Infliximab
Omalizumab
Dupilumab
What are some side effects of biologics?
TB reactivation
Serious infection
Malignancy
TNF inhibitors so risk of demyelination.
