Dermatology pharmacology and prescribing

Question 1

What are the current pharmacological treatment options available in dermatology?

Answer 1

Immunosuppressant medication

Biologic medications

Question 2

Who approves dermatological medicine in the UK?

Answer 2

MHRA - Medicines and Healthcare products regulatory agency

EMA - European medicines agency

SMC - Scottish Medicines consortium

Question 3

When are the categories of medicines which are not licensed?

Answer 3

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

Question 4

What is Pharmacology?

Answer 4

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

Question 5

What factors are associated with poor adherence to prescriptions?

Answer 5

Psychiatric comorbidities

Slower acting agents

Multiple applications per day

Lack of patient education

Cosmetic acceptability of treatments

Unintentional non-adherence

Question 6

What form is a drug in - when inside a topical cream?

Answer 6

Vehicle + active drug

The vehicle is a pharmacologically inert, physically and chemically stable substance that carries the active drug

Question 7

What factors affect the absorption of a drug?

Answer 7

Concentration

Base/vehicle

Chemical properties of the drug

Thickness & hydration of the stratum corneum

Temperature

Skin site

Occlusion

Question 8

What are the different types of vehicles that can carry an active drug in a topical treatment?

Answer 8

Solution

Paste

Cream

Spray powder

Lotion

Shampoo

Gel

Ointment

Foam

Paint

Tape

Question 9

Topical steroids are one of the most commonly seen topical treatments

What are they?

Answer 9

Treatment of inflammation and irritation of the skin

The drug has anti-inflammatory and immuno-suppressive properties

Question 10

How do topical steroids work?

Answer 10

Anti-inflammatory & immuno-suppressive by:

• They regulate pro-inflammatory cytokines
• Suppress fibroblast, endothelial, and leukocyte function
• Stimulate Vasoconstriction
• Inhibit vascular permeability

Question 11

What are the side effects of topical steroids?

Answer 11

• Thinning /atrophy
• Striae
• Bruising
• Hirsutism
• Telangiectasia
• Acne/rosacea/perioral dermatitis
• Glaucoma
• Systemic absorption
• Cataracts

Question 12

What systemic treatments are available in dermatology?

Answer 12

Retinoids - vitamer of Vitamin A

Traditional immunosuppressants

Biologics (also immunosuppressive)

Question 13

How do Retinoids work?

Answer 13

Vitamin A analogues (vitamers) that:

• Normalise keratinocyte function
• have Anti-inflammatory and anti-cancer effects

Question 14

What are the 4 Retinoid medicines used in the UK and what are they used to treat?

Answer 14

Isotretinoin - used to treat Acne

Acitretin - used to treat Psoriasis

Bexarotene - used to treat Cutaneous T cell lymphoma

Alitretinoin - used to treat Hand eczema

Question 15

What are the contraindications to using Retinoids?

What are their potential side effects?

Answer 15

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

Question 16

What are the different immunosuppressive treatments available for inflammatory skin disorders?

Answer 16

Oral steroids

Azathioprine

Ciclosporin

Methotrexate

Mycophenolate mofetil

Question 17

What are the risks of taking immunosuppressive medications?

What should be monitored in people taking immunosuppressive medication?

Answer 17

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>}

Question 18

What are biologics?

Answer 18

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

Question 19

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?

Answer 19

Suffix ‘-cept’ means that it is a receptor fusion

Suffix ‘-mab’ is used to denote monoclonal antibodies

Question 20

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

Answer 20

zu - humanised

ix - chimeric

u - fully human

li or l - immunomodulator

Question 21

What are the contraindications to using biologics?

Answer 21

Impaired renal/liver function

Latent TB

Immunocompromised