18 - Dermatology Common Drugs Flashcards
What are some of the different formulations of emollients and what are they prescribed for?
Formulations
- Aqueous cream,
- Ointment
- Liquid paraffin
- White soft paraffin in equal parts (50:50)
Indications
- Rehydrate skin and re-establish the surface lipid layer
- Useful for dry, scaling conditions and as soap substitutes
What are some of the adverse effects of emollients?
- Irritant or allergic reactions due to perfumes or preservatives
- Flammable if contain paraffin
- Pump dispensers minimise the risk of bacterial contamination; if using a pot, use a clean spoon / spatula every time to reduce risk
What is the potency ladder with topical steroids?
What are some side effects of topical steroids for the treatment of eczema?
- Skin atrophy
- Telangiectasia
- Striae
- Acne
- Perioral dermatitis
- Allergic contact dermatitis
- May mask / cause / exacerbate skin infections
What are some of the side effects of long term oral steroids use for eczema?
- Cushing’s syndrome
- Immunosuppression
- Hypertension
- Diabetes
- Osteoporosis (give bone-protection alongside)
- Cataracts
- Steroid-induced psychosis
- Fluid retention
Why should you avoid oral corticosteroids in psoriasis?
- Risk of unstable disease
- Can develop into pustular psoriasis
What are some of the side effects of anti-histamines used in eczema?
Sedating Antihistamines e.g Chlorphenamine
- Sedation
- Anticholinergic effects (e.g. dry mouth, blurred vision, urinary retention, constipation, acute angle closure glaucoma)
How is dermatitis herpatiformis diagnosed?
Skin biopsy
What is the summary of treatment for eczema? (ladder)
Treated as maintenance and flare ups
Why are topical calcineurin inhibitors used in the treatment of atopic eczema, how do they work and what are some examples of these?
- Steroid sparing agents when steroids are not controlling symptoms but the risk of side effects outweighs the benefits
- Suppress overactivity of T-cells
- Tacrolimus Ointment (Protopic) if severe or Pimecrolimus cream (Elidel) if moderate
What are some side effects and contraindications of topical calcineurin inhibitors?
Side Effects
- Skin irritation (e.g stinging/burning)
- Photosensitivity
- Increased risk of skin cancer and lymphoma
Contraindications
- Do not use near eyes or mucous membranes
- Do not use in infected areas or people susceptible to infections, e.g HSV, as increased risk of developing infection in area used
- Immunodeficiency
What are some of the side effects of oral aciclovir?
- GI upset
- Raised liver enzymes
- Reversible neurological reactions
- Haematological disorders
What is the aim of prescribing anti-virals in shingles?
Reduce the incidence of post-herpetic neuralgia
What antibiotic class has a risk of TEN?
Penicillins
How do you explain to a patient how to apply topical calcineurin inhibitors?
Applied thinly twice a day when active eczema starts and then when cleared continued as a maintenance only twice a week.
Do not apply steroid cream to the same areas
Tacrolimus: Apply 2 hours after emollient
Pimecrolimus: Apply to dry skin then add emollient
Methotrexate is an immunosuppressant that can be used for eczema and psoriasis. How does it work and how is it taken?
Dihydrofolate reductase inhibitor, leading to nitric oxide synthase uncoupling and increased sensitivity of T cells to apoptosis, thereby diminishing immune responses
Only take ONCE A WEEK with folic acid co-prescribed
Can take 8-12 weeks to take effect
What is some pre-treatment screening and monitoring after starting that needs to be done with Methotrexate?
Pre-treatment: Pregnancy test, FBC, U&Es, LFTs, Start contraception, ?CXR, ?Viral Serology
Monitoring (every 1-2 weeks initially then every 2-3 months): FBC, U+Es, LFTs
Report any signs of infection e.g sore throat
What are some side effects and contraindications for the use of Methotrexate in Psoriasis and Eczema?
Side Effects:
- Bone marrow suppression (need to report any infection symptoms)
- GI upset
- Mouth ulcers
- Liver and Lung fibrosis (rare but can develop if also got RA)
Contraindications
- Immunodeficiency syndromes
- Active infections
- Taking trimethoprim can increase risk of bone-marrow suppression
What are some pieces of advice to give patients when starting methotrexate?
- Avoid live vaccines
- Highly teratogenic so both men and women should use contraception whilst using and for 6 months after stopping
- At increased risk of infections. If develop dry cough, diarrhoea, fever or any symptoms need to report as could be toxicity and bone-marrow suppression
- Take care when using with trimethoprim as bone marrow suppression risk
- Avoid alcohol due to liver damage risk
- Need folic acid co-prescribed
Azathioprine is an steroid-sparing immunosuppressant that can be used off-licence for atopic eczema. What is some pre-treatment screening that needs to be done and monitoring that needs to be done after starting this drug?
Pre-treatment: TPMT levels as if low then risk of bone marrow suppression
Monitoring (at least every 3 months): FBCs, LFTs, U+Es
Takes 4-6 weeks to show effect so not useful for acute flares like ciclosporin is
What are some side effects and contraindications for the use of Azathioprine?
Side effects:
- Nausea, Diarrhoea, Loss of appetitie
- Pancreatitis
- Bone marrow suppression
- Increased risk of skin cancers and lymphomas
- ‘Flu-Like Symptoms’ due to allergy
Contraindications:
- Low levels of TPMT
- Do not have live vaccines
Ciclosporin is a steroid-sparing immunosuppressant used in eczema and psoriasis. How does this drug work and why is this immunosuppressant sometimes preferred?
Inhibition of the production of cytokines involved in the regulation of T-cell activation. Calcineurin Inhibitor
- Faster acting
- Not as teratogenic so not so bad if fall pregnant
- Can still drink alcohol
What are some of the side effects of ciclosporin?
SIDE EFFECTS INCREASE OVER TIME SO SHOULD ONLY USE FOR 12 MONTHS!!!!!!
- Reduced renal function (long term)
- Hypertension (long term)
- Gingival hyperplasia
- Hyperlipidaemia
- Skin cancer
- Hyperglycaemia
- GI upset,
- Fatigue and tremor
- Hypertrichosis
What are the different types of phototherapy used in psoriasis and eczema?
1. Broadband UVB (full UVB spectrum used): Psoriasis, Eczema but rarely used
2. Narrowband UVB (more effective): Severe Psoriasis & Eczema
3. PUVA (Psoralen+UVA): Psoriasis (if UVB not effective), Vitiligo, Cutaneous T-cell lymphoma
What are some of the side effects of phototherapy?
Short-term:
- Sun burn
- Dry itchy skin
- Polymorphic light eruption (sunlight-induced rash)
- Cold sores and Eczema Herpeticum
- Initial worsening of skin disease
- Psoralen: Nausea so take with food
Long-term: Premature skin ageing, skin cancer
What is the summary of treatment for psoriasis?
What are some examples of Vit D analogues used in the treatment of psoriasis and how does this topical treatment work?
- Calcipotriol, Tacalcitol, and Calcitriol
- Can be combined with steroid in gel/ointment for short term use
- Help regulate the immune system and slow the overgrowth of skin in psoriasis
Apart from Steroids and Vit D analogues, what are some other topical treatments for Psoriasis?
Coal tar: good for scalp psoriasis, can stain, photosensitivity
Dithranol: may stain the skin purple/brown, put on for ten minutes then wash off, only apply to scales not normal skin
Calcineurin Inhibitors: Protopic
Who is offered Acitretin in psoriasis patients and how does this work?
- If not responded to phototherapy and topical treatments.
- Also for papulopustular psoriasis on hands and feet
- Can take alongside phototherapy treatment
- Taken orally once a day with food
They do not suppress the immune system, they are a Retinoid (vitamin A analogue) that slow skin cell reproduction
What are some side effects of Acitretin?
- Birth defects (need contraception 1 month before and for 2 years after stopping)
- Dry mucous membranes
- Burning sensation or itching on the skin
- Hair loss
- Blurred vision
- Muscle pain
What are some of the side effects of Apremilast?
- D+V
- URTIs
- Depression and suicidal thoughts
When are biologics used in Psoriasis and what are some examples of the biologics used?
Used when
- Phototherapy, Methotrexate, Ciclosporin and Acetretin have failed/contraindicated
- Psoriasis has a large impact on physical, psychological or social functioning
- Psoriasis is extensive or severely localised with functional impairment
What are some side effects of biologics (both in use for eczema and psoriasis)?
Local: redness, swelling, bruising at the site of injection
Systemic: allergic reactions, flu-like symptoms, infections, hepatitis, demyelinating disease, heart failure, cancer, TB reactivation
What is some essential pre-screening needed before initiating biologics?
- Screen for TB, Hep B & C, HIV, VZV
- CXR
- Urine dip
What are some tools used to define the severity of a patients Psoriasis?
Psoriasis Area Severity Index (PASI): used to measure the severity and extent of psoriasis
Dermatology Life Quality Index (DLQI): used to measure the impact a skin disease is having on a patients’ quality of life
What is the summary of management for Acne Vulgaris?
Comedonal: Topical retinoid (Adapalene e.g) +/- benzoyl peroxide. If doesn’t work try Azelaic acid
Mild Pustular: Benzoyl peroxide (to reduce bacterial resistance) with either a topical retinoid OR topical antibiotic
Not responding to above or Severe: Combined topical PLUS systemic antibiotic e.g Tetracyclin or Macrolide if pregnant or <12. Try for 3/12. Could also try COCP (not POP, may make worse)
Still not responding: Oral Isotretinoin, High dose oral abx, Dianette
What are some examples of topical antiseptics and topical antibiotics and what are their side effects?
Antiseptics: chlorhexidine, cetrimide, povidone-iodine
Antibiotics: fusidic acid, mupirocin (Bactroban), neomycin
Side effects: Local skin irritation/allergy
What are some examples of oral antibiotics used for acne and what are their side effects?
Tetracyclines (Doxycycline, Lymecycline): teeth staining in <12 years, photosensitivity, Nausea
Macrolides (Erythromycin, Clarithromycin): GI upset
What are some of the side effects of isotretinoin and some drugs that can interact with this drug?
- Dry skin, lips, eyes
- Photosensitivity (SPF 50 and cover up)
- Depression and suicidal thoughts
- Hepatotoxicity
- Hyperlipidaemia
- Myalgia
- Teratogenicity
What drugs have an increased risk of TEN?
