Pharmacology of Arthritis Flashcards
What are the functions of NSAIDs?
Anti-inflammatory
Analgesic
What are examples of NSAIDs?
Ibuprofen Naproxen Diclofenac Indometacin Etodolac
What are indications for NSAID use?
Inflammatory arthritis
Mechanical MSK pain
Pleuritic/ pericardial pain
What are some adverse effects of NSAIDs?
Dyspepsia Oesophagitis Gastritis Peptic ulcer Small/ large bowel ulceration Renal impairement Increased CV events Fluid retention Wheeze Rash
When should a DMARD be used in inflammatory arthritis?
Within 3 months of symptom onset
Are DMARDs slow or fast acting?
Slow acting - weeks to months
What is the mode of DMARDs?
Pure anti-inflammatory with no direct analgesic effect
Modify the disease progression and reduce the rate of joint damage
What are the commonly used DMARDs?
Methotrexate
Sulphasalazine
Leflunomide
Hydroxychloroquine
What is the mode of action of methotrexate?
Folate antagonist
How can DMARDs be administered?
Orally
Subcutaneous
What is methotrexate used in?
RA
Psoriatic arthritis
CTD
Vasculitis
What are the adverse effects to methotrexate?
Leucopenia/ thrombocytopenia Hepatitis/ cirrhosis Pneumonitis Rash/ mouth ulcers Nausea/ diarrhoea
What blood tests are required for methotrexate use?
FBC
LFTs
Can methotrexate be used in pregnancy?
No it is teratogenic
Must be stopped at least 3 months before conception in females AND males
Describe leflunomide?
Simliar efficacy and side effects to methotrexate
Also teratogenic but has a very long half life to wash out is required
When is sulfasalazine used?
Often used in combo with methotrexate in early inflammatory arthritis
What are the adverse effects of DMARDs?
Nausea Rash/ mouth ulcers Neutropenia Hepatitis Reversible oligozoospermia
What monitoring needs to be done for patients on sulfasalazine?
FBC
LFTs
What is the function of hydroxycholorquine?
No effect on joint damage
Used in CTD for skin, fatigue and joint pain
In what conditions is hydroxychloroquine used?
SLE
Sjogren’s
RA
What is a rare but serious adverse effect of hydroxychloroquine?
Retinopathy
What are biologics?
Drugs designed to target specific aspects of the immune system found to be implicated in inflammatory arthritis
What are common targets of biologics?
TNF
CD20 B cells
IL-6
IL-17, 12 and 23
What is anti-tnf therapy licensed for?
RA
Psoriatic arthritis
Ankylosing spondylitis
How is anti-tnf therapy administered?
Subcutaneous injection
What are examples of anti-tnf therapies?
Etancercept
Infliximab
In RA, who will qualify for anti-TNF therapy?
High disease DS28 score - 5.1 or higher
Use of previous DMARDs
What are adverse effects of anti-TNF therapy?
RIsk of TB (always check for latent TB)
Increased risk of skin malignancy
Contraindicted in pulmonary fibrosiis and heart failure
What drugs are used for the acute treatment of gout?
Colchicine
NSAIDs
Steroids - oral or IM
What is a common adverse effect of colchicine?
Diarrhoea
What drugs can be used for gout prophylaxis?
Allopurinol
Febuxostat
Uricosurics
What is the mode of action of allopurinol?
Xanthine oxidase inhibitor
What are the adverse effects of allopurinol?
Rash (vasculitis)
Azathioprine interaction causing marrow aplasia
What is the mode of action and indication for febuxostat?
Xanthine oxidase inhibitor
Used in those who cannot tolerate allopurinol and those with renal impairment
What are the indications of corticosteroid use in rheumatology?
CTDs
Polymyalgia rheumatica/ GCA
Vasculitis
RA
How can corticosteroids be administered?
PO Intra-articular Soft tissue injections IM IV
What are the adverse effects of corticosteroids?
Weight gain - centripetal Muscle wasting Skin atrophy Osteoporosis Diabetes Hypertension Cataract Glaucoma Fluid retention Adrenal suppression Immunosuppression AVN of femoral head
How can you reduce corticosteroid toxicity?
Use lowest possible dose for as short a time as poss
Consider steroid sparing agents
Osteoporosis prophylaxis
Watch CV risk
