Dermatology, Pharmacology and Prescribing

Question 1

Who licences medication in scotland?

Answer 1

SMC - Scottish medicines consortium

Question 2

What are the causes of prescription errors?

Answer 2

•Lack of knowledge

–About the patient, the medication, allergies

• Mistake writing/generating the prescription
• Poor communication
• No local or national guidelines
• Pharmacy/medicine info service

Question 3

What is the definition of pharmacokinetics and pharmacodynamics?

Answer 3

Pharmacokinetics - the effect of the body on the drug/getting the drug to site of action

Pharmacodynamics - the effect of the drug on the body once it gets to site of action

Question 4

What are the factors that should be considered regarding pharmacodynamics in different patients?

Answer 4

–Age of patient

–Pregnancy risk (some drugs may be teratogenic)

–Drug interactions

–Pharmacogenetics

Question 5

Who is more likely to stick to their medication?

Answer 5

–Female

–Married

–Employed

–Not paying for their prescriptions

–Increasing age

Generally educated patients.

Question 6

What factors are associated with poor adherence/compliance?

Answer 6

• Psychiatric co-morbidities
• Slower acting agents
• Multiple applications per day
• Lack of patient education
• Cosmetic acceptability of treatments
• Unintentional non-adherence

Question 7

In Derm, drugs can be given X or Y

Answer 7

X = TOPICALLY

Y = SYSTEMICALLY

Question 8

Topical Drugs are made up of X and Y

Answer 8

X = VEHICLE

Y = ACTIVE DRUG

Question 9

What is a vehicle when discussing topical drugs?

Answer 9

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

Question 10

Name some types of vehicle?

Answer 10

Solution

Paste

Cream

Spray powder

Lotion

Shampoo

Gel

Ointment

Foam

Paint

Tape

Question 11

Give examples of active drugs given topically?

Answer 11

Corticosteroid

Chemotherapy

Antibiotic

Parasiticidals

Antiviral

Coal Tar

Dithranol

Anti-inflammatory

Vitamin analogues

Salicylic acid

Question 12

What factors affect absorption?

Answer 12

• Concentration
• Base/vehicle
• Chemical properties of the drug
• Thickness and hydration of stratum corneum
• Temperature
• Skin site
• Occlusion

Question 13

What is the function of topical steroids?

Answer 13

Anti-inflammatory

Immunosuppressice

Also vasoconstrict

Also inhibit vascular permeability

Question 14

What is the finger tip unit?

Answer 14

Topical Steroids often administered in fingertip units.

About 0.5 grams - should treat the area double the size of one hand

Question 15

What conditions should topical steroids be used for vs NOT used for?

Answer 15

Used for - Psoriasis and Eczema

NOT used for - Acne Vulgaris and Rosacea

Question 16

What are the side effects of topical steroids?

Answer 16

• Thinning /atrophy of skin (especially in thin areas eg eyelids)
• Striae
• Bruising
• Hirsutism - thick black male like hair in females
• Telangiectasia - thin red thread like vessels
• Acne/rosacea/perioral dermatitis
• Glaucoma and cataracts
• Systemic absorption

Question 17

What skin condition can arise after stopping a course of topical steroids?

Answer 17

Perioral dermatitis

Treatment for which is stopping steroids and using emolient

Question 18

What are the systemic treatments used in dermatology?

Answer 18

Retinoids

Traditional immunosuppressants

Biologics (also immunosuppressive)

Question 19

What are retinoids and what are their function?

Answer 19

Vitamin A anologues

They normalise keratinocyte function

Anti-inflammatory and anti-cancer effects

Question 20

What common derm conditions can Retinoids be used for?

Answer 20

Acne Vulgaris

Acne Rosacea

Question 21

What are the four different oral agents (retinoids) and their uses

Answer 21

Acne - Isotretinoin

Psoriasis - acitretin

Cutaneous T cell lymphoma - bexarotene

Hand eczema - alitretinoin

Question 22

What are the risks associated with retinoids?

Remember you need to do regular blood tests to check LFTs

Answer 22

Teratogenic - DO NOT GIVE TO FEMALES OF CHILD BARING AGE unless confirmed on birth control

Cheilitis (dry lips)

Xerosis (dry skin)

Increase in transaminases

Increase in triglycerides

Rarely psychiatric, eye, bone side effects

Question 23

What are the immunosuppressants used for the treatment of inflammatory skin disorders?

Answer 23

• Oral steroids
• Azathioprine
• Ciclosporin
• Methotrexate
• Mycophenolate mofetil

Question 24

What are the risks associated with immunosuppressants?

Answer 24

Malignancy

Serious unfection

Because they have broad spectrum of action

Question 25

What are the blood tests needed in association with using immunosuppressants?

Answer 25

–FBC (esp in methotrexate and azathioprine)

–Renal function (esp ciclosporin)

–Liver function (esp methotrexate)

Question 26

How are biologics made?

Answer 26

Genetically engineered proteins derived from human genes

Designed to inhibit specific portions of the immune system

Question 27

What do the suffix’es cept and mab mean?

Answer 27

cept - genetically engineered fusion protein

mab - monoclonal antibodies

Question 28

What are the infixes that immediately precede mab?

Answer 28

zu - humanised

ix - chimeric

u - fully human

li/l - immunomodulator

•E.g.adalimumab = immunomodulator fully human monoclonal antibodies

Question 29

Give an example of a biologic that is used to treat plaque psoriasis in the UK

Answer 29

Etanercept

Adalimumab

Infliximab

For chronic spontaneous utricaria - omalizumab

Question 30

What are the risks associated with biologic agents?

Answer 30

•Risk of infection

–TB reactivation

–Serious infection

–Avoid live vaccines eg yellow fever (but can have flu vax)

• Risk of malignancy
• TNF inhibitors – risk of demyelination

Question 31

Biologics have been described as revolutionary for what condition?

Answer 31

Melanoma - ~20% 5 year survival in stage 4 disease