Osteoarthritis and Rheumatoid Arthritis Flashcards
Name the csDMARDs
MTX, sulfasalazine, leflunomide, hydroxychloroquine, ciclosporine
Name the tsDMARD
Tofacitinib
Name the 5 classes of bDMARDs and their drugs
anti-TNF: infliximab, adalimumab, golimumab, etanecept
IL-1R antag: anakinra
Anti-IL-6:L tocilizumab
Anti-CTLA4: abatacept
Anti CD20: rituximab
What type of drug is MTX (csDMARD) and how can it be administered?
Folic acid analogue
PO (variable absorption), SQ or IM
Describe MTX’s MOA
- inhibits ATIC and AICAR = increasing adenosine levels,
- inhibits dDHFR = decreasing purine synthesis
- results in anti-proliferative effects on T cells + inhibition of macrophage functions + decrease in in pro-inflammatory cytokines, adhesion molecules, chemotaxis and phagocytosis
What are SE (and rare and serious ones) of MTX? (4+3)
SE: n&v, mouth and GI ulcers, hair thinning
Rare and serious: leukopenia, hepatic fibrosis and pneumonitis
How can MTX side effects be kept to a minimum
administration of concomitant folic acid or folinic acid given 12-24h after MTX to decrease its toxicity levels
Why is folinic acid more effective than folic acid
It is rapidly converted to N5 and N10-methylene-FH4, bypassing DHFR activity, making it more efficient at rescuing methotrexate toxicity
What are 3 positive effects of sulfasalazine (csDMARD)
- decreased IgA and IgM rheumatoid factors
- suppression of macrophages, T and B cells
- decrease in inflammatory cytokines (eg. IL-1β, TNF, IL-6)
What are SE of sulfasalazine (csDMARD)
n&v, HA, rash, hemolytic anemia, neutropenia, reversible infertility in men
What are 4 positive effects of leflunomide (csDMARD)
- inhibits dihydroorotate dehydrogenase
- decreases pyrimidine synthesis and growth arrest at G1 phase
- inhibits T cell proliferation and B cell autoantibody production
- inhibits NF-κB activation pro-inflammation pathway
What is the consideration for past leflunomide use in pregnant patients?
Very long half life (years after dosing) so cholestyramine wash-out may be administered for example before pregnancy
What are SE of leflunomide?
diarrhea, liver enzyme elevation, alopecia, weight gain, teratogenic
What are 3 positive effects of hydroxychloroquine (csDMARD)?
- reduces MHC class II expression and antigen-presentation
- reduces TNF-α and IL-1 and cartilage resorption
- antioxidant activity
What are SE of hydroxychloroquine?
n&v, stomach pain, dizziness, hair loss, ocular toxicity
How should JAK inhibitors like tofacitinib be used?
may not be the most useful alone, but have shown great efficacy when used in combination eg. combining tofacitinib with MTX or another csDMARD
monotherapy in patients with intolerance to MTX and is effective in MTX- or multiple bDMARD-refractory RA
tsDMARDs should NOT be combined with bDMARDs
What is the MOA for tofacitinib (tsDMARD)?
Janus kinase (JAK) pathway inhibitor, therefore blocking cytokine production
What are SE of tofacinib
cytopenia, immunosuppression (resulting in opportunistic infections), anemia, hyperlipidemia
Arrange anti-TNF bDMARDs according to immunogenecity
The more humanised the biologic, the less immunogenic it is (infliximab > adalimumab > golimumab > etanercept)
What are anti-TNF bDMARD half lives like?
Monoclonal antibodies have half-lives of 1-2 weeks while etanercept has a half-life of about 70 hours
How does anakinra (IL-1R antag) compare to anti-TNF bDMARDs?
less effective than anti-TNF bDMARDs
What are SE of anakinra (IL-1R antagnoist)
infections, injection site reactions