13. RA treatment and DMARDS - Robson Flashcards
What is the prevalence of RA?
1% of the population
How many new cases of RA are diagnosed each year?
Approximately 12,000
What joints in the hands are affected by RA?
MCP joints and proximal IP joints
Is RA symmetrical or non-symmetrical in nature?
RA is symmetrical
Is OA symmetrical or non-symmetrical in nature?
OA is non-symmetrical
In severe cases of RA, which joints will be affected?
In severe cases, most joints will be affected over time
What is the 2010 ACR/EU LAR criteria for diagnosing new patients with RA?
At least one swollen joint - no other explanation
A score of or greater than 6/10
What is the scoring system for the diagnosis of RA?
LOOK AT TABLE IN LECTURE 13/PBL 4
What is the first line of management for RA?
First line is the same as OA - pain relief
How is the first line of management of RA carried out?
Start with the analgesic ladder
Why might a patient not be able to be prescribed standard NSAIDS for pain relief?
What should be prescribed instead?
If they have comorbidites e.g. from cox-1
Cox-2inhibitors
What is the next line of treatment for RA after pain relief?
DMARDs
What are DMARDs?
Disease Modifying Anti-Rheumatics
What are the two different types of DMARDs?
Conventional DMARDs
Biologicals
What is the main mechanism for conventional DMARDs?
Used as immune suppressants
What is the gold standard conventional DMARD?
Methotrexate
How do biologicals (DMARDs) work?
These are TNFa blockers
How should biological DMARDs be used?
These must be used alongside a conventional DMARD as an anchor - typically methotrexate
What is the role of adjunct therapy in the treatment of RA?
Oral corticosteroids may be used only in a particularly bad flare - to get it back under control
When is the best time to initiate treatment of RA?
Want to try and treat it AS SOON AS POSSIBLE for the best prognosis
Ideally start treatment within three months prior to any joint damage
On what kind of dosage of medication should you start for treatment on RA?
VERY HIGH - then once you have control of the disease - reduce the dosage of the drug to be able to maintain the condition
Can then add increased dosage when required e.g. if there is a flare
What is the mechanism of action of methotrexate?
Folate (folic acid) inhibitor (antagonist)
In whom can methotrexate not be used for the treatment of RA?
Pregnant women - folate inhibitor
How frequently must methotrexate be taken?
Take it once a week - same time and day each week
What dosage should initially be taken of methotrexate?
2.5mg tablets
Start between 5-10mg per week (2-4 tablets per week)
How long does it take for methotrexate to have a therapeutic effect?
3-12 weeks
What cells are targeted by methotrexate?
Why does this result in side effects?
Any cells that are proliferating - in RA these are immune cells but there are also many other proliferating cells
What are the common adverse effects of methotrexate treatment?
Liver problems and also haematopoetic stem cells producing RBCs and WBCs - anaemic patients with liver damage
Why should patients taking methotrexate have monthly blood tests?
Methotrexate targets prolfierating cells - liver cells and haematopoetic stem cells producing RBCs and WBCs
Give the mechanism of action of methotrexate
Folic acid antagonist
Uses the same transporter as folate - binds to this and glutamate is added to it - becomes the active drug
Active drug inhibits dihydrofolatereductase and also thymidate synthetase
This inhibition stops the synthesis of DNA and RNA production and so cells requiring this for replication are inhibited
Involves purine metabolism