DMARDS:THE MAINSTAY IN RA:TRADITIONAL AND RECENT

1. STATUS OF DMARDS IN
RHEUMATOID ARTHRITIS
DR SOURYA MOHAPATRA
1ST YR PG
DEPT OF PHARMACOLOGY

2. CONTENTS
• INTRODUCTION
• DRUGS USED IN RA
• DMARDS
• CONCLUSION

3. INTRODUCTION
• RA is a chronic inflammatory ds of unknown
etiology marked by symmetric ,peripheral poly
arthritis causing joint damage and physical
disability.
• Age :25-55yrs ,plateaus at age 75yrs and then
decreases.
• Sex : F>M(2-3:1 ).
• Signs and symptoms: early morning joint stiffness,
pain in small joints, swellings(MCP,PIP).

4. CONT..
PATHOLOGICALLY:
synovial inflammation
,proliferation,
focal bone erosions, thinning of
articular cartilage.
The inflammatory mediators
mostly included :T cells,
B cells, plasma cells, dendritic
cells ,mast cells and
granulocytes. T cell comprised
30-50% of the infiltrate.

5. MODALITIES OF RA TREATMENT
1.NSAIDS- Diclofenac, ibuprofen, aspirin,celecoxib.
Used as adjunctive therapy now.
2.GLUCOCORTICOIDS –mostly prednisone
and methyl prednisone.
For acute flare up cases.
3.CONVENTIONAL DMARDS- Methotrexate,
Hydroxychloroquine, Sulfasazine, Leflunomide,gold salts,
minocycline etc.
4.BIOLOGIC DMARDS-Rituximab, abatacept,
adalimumab,infliximab ,certolizumab etc.

6. STATUS OF DMARDs
The current therapeutic landscape of RA includes:
1. Mtx as DMARD being the 1st choice of t/t of early RA.
2. Developement of novel highly efficacious biological that
can be used alone or in combination with Mtx.
3. Comb. Of DMARD regimen over Mtx alone.
• DMARDS(Disease Modifying Anti Rheumatoid Drugs) :Are
the drugs that decrease inflammation, improves signs ,
symptoms and slows the bone damage a/w RA.

7. CONVENTIONAL
DMARDS

8. METHOTRXATE
synthetic non biologic anti-metabolite used as 1st line therapy in 50-70% of RA pts.
MOA:
Inhibition of Amino Imidazole Carboxamide Ribonucleotide Transformylase
(AICAR)and Thymidylate Synthetase.
AICAR accumulation
Competitive inhibition of AMP deaminase
•
• Accumulation of AMP
•
• Conversion to adenosine
Inhibition of inflammation by suppression of macrophages ,dendritic cells ,
lymphocytes , neutrophils and stimulation of apoptosis in these cells.

9. CONT..
• Has 2ndary effects on Dihydrofolate reductase and
this affects lymphocyte and macrophage function.
• Inhibition of proinflammatory cytokines linked to
rheumatoid synovitis.
PK:
• 70% of the drug metabolized after oral
administrtioin.
• t/2:6-9 hrs .
• Excretion: mostly urine,30% bile.

10. CONT..
IN RA:
Dose: 15-25mg wkly . Can be increased upto 30-
35mg wkly f/b folic acid 1 mg /d to decrease toxicity.
• Mtx decreases the rate of appearance of new
bony erosions.
S/E: nausea, mucosal ulcers.
• Dose related hepatotoxicity.
• Leucopenia ,anemia, gi ulceration.
• CI in pregnancy.

11. HYDROXYCHLOROQUINE
non biologic agent .
MOA:
• Suppression of T lymp response to mitogens.
• Decrease leukocyte chemotaxis.
• Stabilization of lysosomal enzymes.
• Trapping of free radicals.
PK:
• Rapidly absorbed in body .
• 50 % protein bound.
• Deaminated in liver.
• t/2: 45 days

12. CONT..
DOSE IN RA:
• 200-400 mg/d orally(UPTO 6.4 mg /kg/d) for
Hydroxy CQ.
• Takes 3-6 mn for response.
• No effect on the bony damage of RA.
S/E :
• Ocular toxicity,so eye examination every 12mn.
• others: nausea ,vomiting ,rashes.

13. SULFASALAZINE
• Synthetic DMARD.
• Metabolized to sulfapyridine and 5-ASA
• Sulfapyridine is the active moeity in RA t/t.
MOA:
• decreases the production of Ig A and Ig M .
• Inhibits release of inflammatory cytokines produced by
macrophages and monocytes.eg.IL-1,6,12 and TNF alpha.
PK:
• 10-20% absorbed orally.
• Another fraction undergoes enterohepatic circulation.
• t/2: 6-17hrs .
• Excreted unchanged in urine.

14. Cont..
In RA:
• decreases the radiologic disease progression.
• Dose :Initial: 500mg BD daily orally.
Maint:1000-1500mg BD daily.
S/E:
• nausea vomiting
• Hemolytic anemia in g6 PD deficient pts.
• Methhemoglobinemia
• Neutropenia in 1-5% of pts.

15. LEFLUNOMIDE
• Non biologic DMARD
MOA:
• Undergoes rapid conversion both in intestine and in plasma to its active
metabolite A77 -1726.
• This inhibits the Dihydro orate dehydrogenase that decreases the RNA
synthesis and arrests stimulated cells in the G1 phase of cell growth.
• Thus inhibition of T cell proliferation and production of autoAb by B cells.
• Also decreases IL-8 and IL-10 Synthesis-and the TNF alpha dependant NFKB
activation.
IN RA:
• Dose : 10-20mg/d
• t/2 :19 days.
• Inhibits bony damage along with Mtx.
SE:
• Diarrhea -25%,wt gain, incr.BP.
• CI in pregnancy.

16. AZATHIOPRINE
• Synthetic DMARD
MOA:
• acts mainly through its metabolite 6- thio guanine
which suppresses the ionosinic acid syn, Bcell and T
cell func, Ig production and IL -2 secretion.
IN RA: decreases progression of bony erosion.
Dose :2mg/kg/d oral daily.
SE:
• bone marrow suppression
• GI disturbances
• Incr.infection,risk and incr. risk of lymphomas.

17. CYCLOSPORINE
• Peptide antibiotic plus non biologic DMARD.
MOA:
• inhibits IL-1 and 2 receptor production,
• inhibits macrophages-T cell interaction and T cell responsiveness.
IN RA:
• Retards the appearance of new bony erosions.
• Dose:3-5mg/kg/d in 2 div. doses.
SE:
• leucopenia, thrombocytopenia,anemia
• Rare: cardiotoxicity and sterility in women on long use.
• Risk of bladder ca also increases.

18. OTHERS
• Mycophenolate mofetil:less efficacy.
• D –penicillamine
• Cyclophosphamide.
• Minocycline,chloroquine.
• Rarely used now –a days

19. BIOLOGICALDMARDS

20. ADALIMUMAB
• Fully human Ig G1 anti TNF monoclonal ab.
MOA:
• complexes with soluble TNF-alpha and prevents its
interaction with p55 and p75 cell surface receptors
resulting in downregulation of macrophages and T cell func.
IN RA: effective both as monotherapy and comb. with MTX
and other DMARDS.
• Dose: 40mg sc every Alternate wk given .
• t/2:10-20d.
SE : increased risk of bact inf.
• Screening of latent TB should be done in every pt before
starting the therapy.

21. INFLIXIMAB
• Chimeric(25% mouse,75% human) Ig G1 monoclonal ab .
MOA:
binds with high affinity to soluble and membrane bound TNF-a thus
inhibiting tnf-a func.
IN RA: with MTX decreases the formation of new erosion more than
MTX alone over 12-24mn.
• Dose: 3mg/kg iv at 0,2,6 wk then every 8wk may increase the
dose upto 10mg/kg every 4 wk and maintenance every 8wks
thereafter.
• t/2:9-12 d.
SE: URTI ,activation of latent TB, increased positive ANA and ds DNA
ab.

22. ETANERCEPT
• Recomb. fusion protein that inhibits TNF alpha.
MOA:
• by blocking TNF alpha and lymphotoxin –a decreases the
inflammatory reaction.
IN RA: used as monotherapy and also with MTX decreasing the
rate of formation of new erosions.
• Dose: 50mg given once wkly or 25mg sc biwkly.
• t/2:4.5 d.
SE:
• increases bact.inf. Mostly soft tissue and septic arthritis.
• Screening of TB should be done before starting therapy.

23. CERTOLIZUMAB
• Recombinant humanised ab fab fragment conjugated
to polyethylene glycol.
MOA:
• Neutralizes membrane bound and soluble TNF alpha in
a dose dependant manner.
IN RA: mod to sev RA.
• Dose: 400mg initially sc at 0 wk ,2wk,f/b 200mg every
other wk.
• t/2:14d.
SE: Tb activation, fungal inf.

24. GOLIMUMAB
• Human monoclonal ab.
• TNF –a antagonist.
MOA:
• has affinity for soluble and membrane bound TNF alpha .
• Neutralizes the inflammatory effects produced by TNF-alpha.
IN RA: with MTX used for mod-sev active RA in adult pts.
• Dose:50mg sc monthly.
• t/2 -14d.
SE: increased TB and fungal infec.
• Latent TB test to be done.

25. TOCILIZUMAB
• Newer biologic humanized ab .
MOA:
• IL-6(pro inflammatory ) Inhibitor.
• Inhibits T cells, B cells, monocytes, fibroblasts, synovial and
endothelial cells.
IN RA: for mod-sev active RA.
• Dose: 4-8 mg /kg iv monthly or
If (<100kg wt) 162 mg sc every other wk and (>100kg)
162mg sc every wk f/b 8mg/kg depending on clinical condition .
• t/2 :11 d for 4mg/kg dose, 13 days for 8mg/kg dose.
SE: TB ,fungal infec, HTN, neutropenia.

26. RITUXIMAB
• Chimeric monoclonal Ab biologic agent.
MOA:
• targets CD-20 B lymp.
• stimulates cell apoptosis .
• decreases inflammation and production of pro inflammatory
cytokines.
IN RA: mod to severe RA ,in combination with MTX in pts with
inadequate response to 1 or more TNF-alpha antagonists.
• Dose: 1000mg iv on day 0 and 14.May be repeated every 24wks.
Pre t/t with 100mg iv methylprednisolone given todecrease
infusion reaction.
SE: rash ,increased bact. Infections.

27. ABATACEPT
• Type of fusion protein.
Moa:
• Inhibits T cell activation by binding to CD 80 and 86 of the APC, blocking
the CD -28 binding and activation of T cells.
IN RA:
• used as monotherapy or in comb. with other DMARDS in pt of mod-sev RA.
• Reduces signs and symptoms of RA including slowing of radiographic
progression.
• Dose : wt based - <60 kg- 500 mg, 60-100kg-750mg, >100kg-1000mg, given
as iv doses at 0,2,4 wk and then every 4wkly or 125 mg sc wkly can be given
otherwise.
• t/2: 13-16d.
SE: increased risk of infection,(URTIS),anaphylactic reactions,
lymphomas rarely.

28. OTHERS
Tofacitinib: Jak 1 and Jak 3 inhibitor which blocks
signalling of recptors for cytokines IL 2,4,7,15,21.
• Dose in RA :5mg bd orally.
Anakinra: recomb form of IL-1 receptor antagonist.
• Dose in RA:100 mg sc daily.

29. CONCLUSION
• Mtx is the DMARD of 1st choice for initial t/t of mod-sev RA.
• But failure of MTX as monotherapy now calls for a change to an effective comb.
regimen.
EFFECTIVE COMB.REGIMEN includes:
1. Mtx+ sulfasalazine+hydroxycq(oral triple therapy)
2. Mtx+ leflunomide.
3 Mtx+ a biological
• A/T 2012 guidelines for RA : they highlight the need to switch or add DMARD
therapy after 3mn of worsening or persistent mod/high ds activity.
• If ds. Still persists after 3mn of intense DMARD therapy ,addition of a biologic agent
is warranted.
• With loss or lack of effectiveness of active TNF Alpha after 3mn one should switch to
another anti TNF or non TNF biologic agent.

30. CONT..
In PREGNANCY:
• hydroxyCQ and sulfasalazine are safest.
Mtx ,leflunomide are CI.
• Safety of biologicals in pregnancy is under study.
In ELDERLY PTS: conv DMARDS and biologic agents are
safe and effective .
• Renal func to be done before MTX therapy.
• The need for early and aggressive t/t of RA as well as
frequent follow up visits for monitoring of drug
therapy has implication for our health care system.