Pharmacology of Arthritis Flashcards
what is the ladder of pain management (WHO)?
non-opioids +/- adjuvant
weak opioid for mild-moderate pain +/- non opioid +/- adjuvant
strong opioid (morphine) +/- non-opioids +/- adjuvant
indications for NSAIDs?
inflammatory arthriitis
mechanical MSK pain
pleuritic/pericardial pain (connective tissue disease)
NSAIDs side effects?
peptic ulceration
renal impairment
increased cardio risk (if taken regularly over long time)
exacerbation of asthma
first line for newly diagnosed rheumatoid arthritis?
methotrexate (first line DMARD)
also use steroids in the short term to help symptoms
when should methotrexate be started?
within 3 months of symptom onset
next step if RA doesn’t responds to standard DMARD therapy?
biological agents
how do DMARDs work?
slow acting
only anti inflammatory - no analgesic effect
improve standard ab tests (CRP?ESR)
reduce rate of joint damage
does DMARD therapy need to be monitored?
yes
do DMARDs improve pain?
no
best treatment method for RA treatment?
early intervention (first 3 months) aggressive treatment
common DMARDs?
methotrexate
sulfasalazine
leflunomide
hydroxychloroquine
what is a risk of methotrexate?
can cause problems in pregnancy
must stop taking it before 3 months before trying to concieve
how can methotrexate be administered?
oral
IV
what is methotrexate?
folate antagonist
methotrexate side effects?
pneumonitis low WCC thrombocytopenia hepatitis/cirrhosis rash/mouth ulcers nausea
which drug is similar to methotrexate?
lelflunamide has similar effectiveness and side effects
problem with leflunamide?
long half life so has to be washed out
sulfasalazine side effects?
nausea rash/mouth ulcers neutropenia hepatitis reversible oligozoospermia (reduced sperm count)
is leflunamide safe in pregnancy?
yes
what does hydroxychloroquine do?
doesn’t have an affect on joint damage
used more in connective tissue disease - lupus
targets of biological agents?
TNF
CD 20 B cells
interleukin 6
interleukin 17, 12 and 23
do biologics work for everyone?
no
but generally more effective than DMARDs
do biological agents have side effects?
yes
what is anti TNF used for?
RA
psoriatic arthritis
ankylosing spondylitis
how is anti TNF given?
sub cutaneous injection
examples if anti TNF?
etanercept
infliximab
adalinumab
criteria for anti TNF use?
DAS28 >5.1
use of previous standard DMARDs
side effects of anti TNF?
re-activation of latent TB
increased infection risk
increases skin cancer risk (only slightly)
exacerbate heart failure (contraindicated if patient has severe heart failure)
does anti TNF cause foetal abnormalities?
no
therefore safe n pregnancy
does inflammatory/rheumatoid arthritis improve or worsen in pregnancy?
improve generally
what are the 2 components of gout treatment?
treat acute flare
gout attack prophylaxis
what is not used during a flare of gout?
allopurinol
if someone is already on allopurinol and has a flare, do you stop it?
no
other gout medications
naproxen
colchicine
prednisolone
intramuscular steroid
treatment for actute episode of gout?
colchicine
NSAIDs
steroids
gout prophylaxis?
lower urate
- allopurinol (first line)
- febuxostat (used if theres renal failure?)
- uricosurics
what is allopurinol side effcts?
rash (vasculitis) - common in elderly and if theres renal failure
azathioprine interaction - can suppress bone marrow
rarely causes marrow aplasia
what is used if allopurinol not tolerated (e.g renal failure)?
febuxostat
goal for urate?
<360 micro moles per litre
- always monitor during treatment
how long should steroids be used?
as short a time as possible
side effects of steroids?
loss of bone density (osteoporosis risk) can contribute to diabetes development can cause weight gain (mainly oral if over long time) muscle wasting skin atrophy
how can steroid risk be reduced?
use for short time
use lowest dose possible
consider steroid sparing agents
prophylaxis for osteoporosis
possible cause of cough and breathlessness with bilateral crackles 12 weeks after starting methotrexate?
methotrexate pneumonitis
- due to quick onset
- could have been pulmonary fibrosis if over years of treatment
what other DMARD could you use instead of methotrexate if trying to conceive?
sulfasalazine
- must be off methotrexate for 3 months before conceiving
