Dermatology pharmacology and prescribing Flashcards
What are the current pharmacological treatment options available in dermatology?
Immunosuppressant medication
Biologic medications
Who approves dermatological medicine in the UK?
MHRA - Medicines and Healthcare products regulatory agency
EMA - European medicines agency
SMC - Scottish Medicines consortium
When are the categories of medicines which are not licensed?
Unlicensed:
- Not approved for use in the UK
‘Off-label’:
- licensed medication that is being used for an unlicensed indication
‘Specials’:
- unlicensed dermatological preparations used on special occasions
What is Pharmacology?
The branch of medicine concerned with the uses, effects, and modes of action of drugs
Incorporates:
Pharmacokinetics:
- The effect of the body on the drug
Pharmacodynamics:
- The effect of the drug on the body
What factors are associated with poor adherence to prescriptions?
Psychiatric comorbidities
Slower acting agents
Multiple applications per day
Lack of patient education
Cosmetic acceptability of treatments
Unintentional non-adherence
What form is a drug in - when inside a topical cream?
Vehicle + active drug
The vehicle is a pharmacologically inert, physically and chemically stable substance that carries the active drug
What factors affect the absorption of a drug?
Concentration
Base/vehicle
Chemical properties of the drug
Thickness & hydration of the stratum corneum
Temperature
Skin site
Occlusion
What are the different types of vehicles that can carry an active drug in a topical treatment?
Solution
Paste
Cream
Spray powder
Lotion
Shampoo
Gel
Ointment
Foam
Paint
Tape
Topical steroids are one of the most commonly seen topical treatments
What are they?
Treatment of inflammation and irritation of the skin
The drug has anti-inflammatory and immuno-suppressive properties
How do topical steroids work?
Anti-inflammatory & immuno-suppressive by:
- They regulate pro-inflammatory cytokines
- Suppress fibroblast, endothelial, and leukocyte function
- Stimulate Vasoconstriction
- Inhibit vascular permeability
What are the side effects of topical steroids?
- Thinning /atrophy
- Striae
- Bruising
- Hirsutism
- Telangiectasia
- Acne/rosacea/perioral dermatitis
- Glaucoma
- Systemic absorption
- Cataracts
What systemic treatments are available in dermatology?
Retinoids - vitamer of Vitamin A
Traditional immunosuppressants
Biologics (also immunosuppressive)
How do Retinoids work?
Vitamin A analogues (vitamers) that:
- Normalise keratinocyte function
- have Anti-inflammatory and anti-cancer effects
What are the 4 Retinoid medicines used in the UK and what are they used to treat?
Isotretinoin - used to treat Acne
Acitretin - used to treat Psoriasis
Bexarotene - used to treat Cutaneous T cell lymphoma
Alitretinoin - used to treat Hand eczema
What are the contraindications to using Retinoids?
What are their potential side effects?
Pregnant / childbearing age:
- Retinoids are teratogenic
Side effects include:
- Cheilitis (dry lips) and xerosis (dry skin)
- Increased levels of Transaminases and triglycerides
- Rare - psychiatric, eye, bone side effects
What are the different immunosuppressive treatments available for inflammatory skin disorders?
Oral steroids
Azathioprine
Ciclosporin
Methotrexate
Mycophenolate mofetil
What are the risks of taking immunosuppressive medications?
What should be monitored in people taking immunosuppressive medication?
Risk of malignancy and serious infection
Regular blood test monitoring - in particular:
- FBC - especially with <strong>methotrexate</strong> and <strong>azathioprine</strong>
- Renal function - especially with <strong>ciclosporin</strong>
- Liver function - especially with <strong>methotrexate</strong>
What are biologics?
Next generation in treatment of inflammatory conditions
Genetically engineered proteins derived from human genes that are designed to inhibit specific components of the immune system
Very effective, but expensive
The endings (suffix) to the names of biologics will tell you what type of medication it is
What endings are there and what do they mean?
Suffix ‘-cept’ means that it is a receptor fusion
Suffix ‘-mab’ is used to denote monoclonal antibodies
To fuck up things even more - the names of biologics have certain ‘infixes’ which denote certain things about it. Describe what each of these means:
a) zu
b) ix
c) u
d) li or l
zu - humanised
ix - chimeric
u - fully human
li or l - immunomodulator
What are the contraindications to using biologics?
Impaired renal/liver function
Latent TB
Immunocompromised
