Dermatology Pharmacology and Prescribing

Question 1

How much of hospital admissions are due to adverse drug reactions?

Answer 1

3-6%
Half of these are preventable

Question 2

What makes medication licensed?

Answer 2

Approved for use in UK by MHRA and EMA
High standards
Trial evidence to show positive effect
SMC submission - Scottish Medicines Consortium

Question 3

What are medicine without licence?

Answer 3

Unlicensed - not approved use in the UK
Off label - licensed medication that is being used for non-licensed indication
Specials - unlicensed dermatological preparations

Question 4

What are some factors associated with poor adherence?

Answer 4

Psychiatric co-morbidities, slower acting agents, multiple applications per day, lack of patient education, cosmetic acceptability of treatments and unintentional non-adherence

Question 5

What is pharmacokinetics?

Answer 5

The effect of the body on the drug

Question 6

What is pharmacodynamics?

Answer 6

The effect of the drug on the body

Question 7

What is included in pharmacokinetics?

Answer 7

Route of administration
Distribution
Metabolism - esp. in liver disease
Excretion - esp. in renal disease

Question 8

What is involved in pharmacodynamics?

Answer 8

Individual response to drug
Patient age, pregnancy risk, drug interactions and pharmacogenetics

Question 9

What is a vehicle in pharmacology?

Answer 9

Pharmacologically inert, physically and chemically stable substances that carries the active drug

Question 10

What is topical therapy?

Answer 10

Medication applied to the skin
Vehicle + active drug

Question 11

What are some factors which affect topical absorption?

Answer 11

Concentration, base/ vehicle, chemical properties, thickness and hydration of stratum corneum, temp., skin site and occlusion

Question 12

What are types of vehicles of drugs?

Answer 12

Solution, cream, lotion, paste, paint, spray, shampoo, gel, foam, ointment and tape

Question 13

What are some drugs which are used topically?

Answer 13

Corticosteroid, antibiotic, antiviral, dithranol, vitamin analogues, chemo, parasiticidal, coal tar, anti-inflammatory and salicylic acid

Question 14

Describe topical steroids

Answer 14

Anti-inflammatory and immunosuppressive properties
Regulate pro-inflammatory cytokines
Supress fibroblast, endothelial and leukocyte function
Vasoconstriction and inhibit vascular permeability

Question 15

What is a finger tip unit?

Answer 15

0.5g - can treat area double the size of one hand
Useful for children and charts are available for ages

Question 16

What are some side effects of topical steroids?

Answer 16

Thinning, striae, bruising, hirsutism, telangiectasia, acne, glaucoma, systemic absorption and cataracts

Question 17

What are some systemic treatments in dermatology?

Answer 17

Retinoids
Traditional immunosuppressants
Biologics

Question 18

Describe retinoids

Answer 18

Vitamin A analogues - normalise keratinocyte function and anti-inflammatory and anti-cancer effects
4 different molecules used orally in dermatology

Question 19

What are retinoids effective in?

Answer 19

Acne - isotretinoin
Psoriasis - acitretin
Cutaneous T cell lymphoma - bexarotene
Hand eczema - alitretinoin

Question 20

What are the side effects of retinoids?

Answer 20

Teratogenic
Cheilitis (dry lips) and xerosis (dry skin)
Increased transaminases and triglycerides
Rare - psychiatric, eye and bone side effects

Question 21

Describe immunosuppressants

Answer 21

Treatment of inflammatory skin disorders
Oral steroids, azathioprine, ciclosporin, methotrexate and mycophenolate mofetil
Risk of malignancy and serious infection

Question 22

What monitoring is needed for immunosuppressants?

Answer 22

FBC
Renal function
Liver function

Question 23

Describe biologics

Answer 23

Next generation of treatment for inflammatory conditions
Genetically engineered proteins derived from human genes
Designed to inhibit specific components of immune system

Question 24

What does the suffix -cept and -mab mean for biologics?

Answer 24

-cept indicates it is a receptor fusion
-mab is used to denote monoclonal antibodies

Question 25

What are some infixes for biologics?

Answer 25

Zu - humanised
Ix - chimeric
U -fully human
Li/-l- - immunomodulator

Question 26

What are some current licensed biologics for dermatology conditions?

Answer 26

Psoriasis, Hidradenitis suppurativa, chronic spontaneous urticaria, atopic eczema and pemphigus

Question 27

What are the risks of biologics?

Answer 27

Risk of infection - TB activation, serious infection and avoid live vaccines
Risk of malignancy
TNF inhibitors - risk of demyelination

Question 28

What is the targeted treatment for melanomas?

Answer 28

If BRAF 600 mutation - Vemurafenib and Dabrafenib
Immunotherapies - Ipilumumab and Pembrolizumab