Rheumatology and MSK PPT Flashcards
What radiological changes do you see in OA?
Loss of joint space
Osteophytes
Subchondral cysts
Subchondral sclerosis
What are teh non-pharmacological approaches to OA management?
weight loss if obese/overweight, physiotherapy, appropriate footwear, heat/cool packs, psychological support, assistive devices, joint supports
What pharmacological management option would you try first in someone with OA?
paracetamol +/- topical NSAIDs.
name two adjunct treatments that can be used in OA
topical capsaicin cream.
intra-articular steroid injections
What is the MOA of NSAIDs?
COX1 and COX 2 inhibitors
Name 4 side effects of NSAIDs
GI disturbance, renal insufficiency, salt/water retention, hyponatraemia/hyperkalaemia, CVS effects, hypersensitivity reactions, headaches/dizziness, skin reactiosn
why does the side effect profile of NSAIDs vary?
different drugs have different degrees of selectivity for COX-1 or COX-2.
when prescribing and NSAID, what steps can you take to reduce the risk of GI side effects?
lowest dose for the shortest time.
take with food.
prescirbe PPI alongside (being aware that PPIs carry their own risk).
consider a selective COX-2 inhibitor instead.
what group of people do you have to be cautious with if prescribing a COX-2 inhibitor?
those with ischaemic heart disease or risk factors for MI as it can increase risk of MI
why are NSAIDs contra-indicated in heart failure?
because they increase salt and water retention
why are NSAIDs avoided during 3rd trimester of pregnancy?
anti-prostaglandin effects prevent ductus arteriosus from closing
when would you consider referring a pt with OA for joint surgery?
- once person has been offered all/most non-surgical options
- if joint sx have a substantial impact on their QoL and are refractory to non-surgical treatment.
- if there are major limitations and pain.
is uric acid level a good indicator to rule out gout?
No - it is unreliable in the acute phase. normal uric acid level does nto rule out gout
what is needed to diagnose gout and rule out septic arthritis?
joint aspiration
how are gout crystals described under polarised light?
negatively birefringent, needle shaped
what are gout crystals made of?
monosodium urate
uric acid is the product of catabolism of what?
purines
what do pseudogout crystals look like under polarised light?
positively birefringent, rhomboid/rectangular shaped crystals
what are pseudogout crystals made of?
calcium pyrophosphate (CPP)
Name two medications that can increase risk of gout
diuretics, chemotherapy agents.
allopurinol when first started can precipitate gout becasue it can casue transient incraese in uric acid levels
why should allopurinol not be used in acute gout?
because it can precipitate gout as it can cause an initial transient increase in uric acid levels
what non-pharmacological advice can you give someone with gout?
rest, elevate limb, avoid trauma, ice-pack, basic analgesia with paracetamol.
what is first line drug option for gout?
NSAID or colchicine
what is the MOA of colchicine?
multiple anti-inflammatory actions. inhibits recruitment and action of neutrophil leucocytes in the joint, specific to a gouty joint. overall, prevents activation, migration and action of neutrophils within joint space.
what side effect do you need to stop colchicine immediately for if you get and why?
diarrhoea because it is a sign of it being toxic and destroying the gut lining.
name two contra-indications for colchicine
blood disorders and pregnancy (teratogenic)
name 4 drugs colchicine interacts with
increases toxicity of: macrolides, anti-virals/fungals, CCB, grapefruit juice.
increases risk of myopathy when given with lipid lowering therapy.
what is the length of the colchicine course?
continue to take for 1-2 days after acute attack has resolved. however, it is restrictedto 3-6 days due to risk of toxicity
what lifestyle advice can you give to someone to prevent gout attakcs?
weight loss, reduction in alcohol and red meat/seafood consumption, keep hydrated, regular exercise, low fat dairy products, smoking cessation
how soon after a gout attack would you repeat blood tests to confirm hyperuricaemia?
4-6wks
what is the first line urate lowering therapy available?
allopurinol
should you start urate lowering therapy, such as allopurinol, during a gout attack?
no wait until acute attack has resolved as allopurinol can transiently increase uric acid levels initially.
what is the MOA of allopurinol?
xanthine oxidase inhibitor
how should you monitor allopurinol treatment?
check serum uric acid level and renal function every 4wks until within target range, then annually thereafter
what is the target range of uric acid?
<300 micromol/l
a pt who has been on allopurinol for 2yrs for prevention of gout comes and asks if it can nwo be stopped? what do you do?
explain that treated is usually life long to prevent recurrent attacks, tophi development and hyperuricaemia-induced renal disease (urate nephropathy, renal stones). However, can consider lowering dose to maintain serum uric acid between 300-360. can be more inclined to stop it if modifiable risk factors have been addressed adn a normal serum uric acid lvele has been achieved for many years
what ix would you arrange in someone you supected had inflammatory arthritis?
RF, Anti-CCP, XR of affected joints.
consider FBC, U&Es, LFTs, for baeline.
could do ESR, CRP and PV whcih are usually raised but they may be normal.
how long do DMARDs take to work on average?
3 months
what is the MOA of methotrexate?
dihydrofolate reductase inhibitor. inhibits the enzyme which converts folic acid to tetrahydrofolate (fh4) which prevents cellular replication. also inhibits inflammatory mediators such as IL6, IL8 and TNF-alpha.
which DMARDs are usually first-line in RA?
methotrexate, leflunomide, sulfasalazine, hydroxychloroquine
what could you consider starting at the same time as a DMARD while waiting for it to work?
steroids
what is MOA of sulfasalaziine?
its metabolites, 5-aminosalicylic acid (5-ASA) have antiinflammatory and immunosuppressive effects
which DMARD can turn urine oragne?
sulfasalazine
what allergy makes prescribing sulfasalazine contra-indicated?
aspirin allergy because it’s a salicylate
name 4 side effects of sulfasalazine
GI disturbances, orange secretions, pancreatitis, blood disorders, hepato-renal toxicity, skin reactions, reversibel oligospermia
when are biological therapies indicated in RA?
once steroids, two trials of 6 months of DMARD monotherapy or combo therapy (at least one including methotrexate) have failed.
name 2 TNF-alpha inhibitors used in RA
infliximab, adalimumab, entanercept, golimumab
how is infliximab given and how often?
IV injection. initially 2-4wkly then every 2 months
name 4 side effects of infliximab
hypersensitivity reactions, HF/arrhythmias, skin disorders, lung problems, GI disorders, reports of blood disroders adn infectison
name 5 things you should consdier before starting a pt on infliximab
- pts should be up to date with immunisations before initiating treatment.
- assess for active and latent TB and treat accordingly
- contraception cover is needed for 6 months after last dose.
- monitor for rreactivation of Hep B
- periodic skin examination for non-melanoma skin cancer
how often are doses of methotrexate given?
once a week
name 4 contraindications for methotrexate
active infection, ascites, pleural effusion, severe reanl impairment, teratogenic
name 2 drugs that interact badly whit methotrexate
trimetoprim/co-tirmoxazole (severe BM depression) and NSAIDs (toxicity)
how many months should men be off methotrexate before conceiving?
3-6 months
what 5 important considerations are required when starting a pt on methotrexate?
avoid live vaccines (MMR, yellow fever, typhoid). co-prescribe folic acid to help prevent mucositis and myelosuppression. use appropriate contraception during and for at least 6 months after treatment in men and women
pre-screening tests
what pre-screening tests are needed before starting methotrexate?
baseline FBC, U&Es, LFTs, pregnancy test if appropriate
how often do you need to monitor person on methotrexate when they first start and what tests do you do?
do FBC, renal function and LFTs every 2wks until on stable dose for 6 wks
once a pt is on stable dose of methotrexate, how often should you do monitoring bloods?
monthly FBC, renal funciton and LFTs for 3 months
once pt has been on a stable dose of methotrexate for 3 months, how often shoudl you do monitoring bloods?
every 12wks at least. FBC, renal function and LFTs.
a pt has their methotrexate dose incresed, how often do they need monitoring?
monitor every 2wks until dose is stable for 6wks. then can do monthly for 3 months then every 12wks
