Dermatology pharmacology and prescribing Flashcards
unlicensed
not approved for use in UK
off label
A licensed medication being used for an unlicensed indication
Specials medication
unlicensed dermatological preparations
clinically effective but lack of evidence
Pharmacokinetics
effect of body on the drug
Pharmacodynamics
Effect of drug on the body
Causes of prescription errors
lack of knowledge - patient, medication, allergy
unintentional error in writing of prescription
no guidance
poor communication
Pharmacology
branch of medicine concerned with uses, effects and modes of actions of drugs
What is the preferred route of administration?
topically
Distribution
where the drug gets
Metabolism - disease of what organ important?
liver
Excretion - disease of what organ important?
kidneys
4 factors influencing pharmacodynamics
age
drug interactions
pregnancy risk
pharmacogenetics
Factors which make it more likely the patient will adhere to medication?
female, increasing age, working, married, not paying for prescription
Factors associated with poor adherence to medication
psychiatric unintentional cosmesis implications slower acting agents multiple times a day lack of education
2 components of a topical therapy
vehicle and active drug
What is a vehicle?
pharmacologically inert, physically and chemically stable substance that carries active drug
Factors affecting absorption of a topical therapy
skin site thickness and dehydration location occlusion concentration vehicle temperature chemical properties
List some examples of vehicles
creams, ointments, shampoo, patches, oils, gel, foam, paste, lotion, spray, paint
Some examples of medications given topically
steroids, NSAIDS, salicylic acid, antiviral, antibiotic, chemotherapy, coal tar, vitamin analogues, parasiticidals
How do topical steroids work?
regulate pro-inflammatory cytokines
suppress fibroblasts, endothelial and leukocyte function
vasoconstriction and inhibit vascular permeability
Is % or potency of a topical CCS more important?
potency
What is a finger-tip unit?
0.5g - enough to cover childs hand twice
side effects of topical steroids
thinning/atrophy hirsutism striae bruising glaucoma acne rosacea cataracts telangiectasia
3 systemic treatments in dermatology
retinoids
immunosuppressants
biologics
What are retinoids?
vitamin A analogues
How do retinoids work?
normalise keratinocyte function
anti-inflammatory and anti-cancer
Conditions which use retinoids
acne, psoriasis, cutaneous T cell lymphoma, hand eczema
Disadvantages/side effects of retinoids
teratogenic
psynchiatric, eye, bone - rare
dry lips and dry skin
increase TAG
Risks of immunosuppressives
malignancy and infection
3 important blood tests for those on immunosuppressives
FBC
renal function
liver function
Biologics - what are they?
genetically engineered proteins derived from human genes designed to inhibit specific parts of immune system
Cept
receptor fusion protein
mab
monoclonal anti-body
zu
humanised
ix
chimeric
u
fully human
il
immunomodulatory
2 conditions biologics used in
psoriasis
chronic spontaneous urticaria
Risks of infection consequences of biologics
reactivation of TB
avoid live vaccines
serious infection
2 other disadvantages of biologics
risk of malignancy
TNF inhibitor - risk of demyelination
Biologics in melanoma
poor prognosis - help to improve this
BRAF 600 mutation
immunotherapies
5 year survival for melanoma
20%
