Rheumatoid Arthritis Flashcards
Pathophysiology of RA
• Chronic, systemic inflammatory disease of unknown cause
– T-cell activation -> cytokines -> inflammatory cascade
– B-cell activation (through-cell interaction) -> terminate by B-cell lymphocytes -> differentiated rheumatoid factor (RF), anti-cyclic citrullinated antibodies
• Impacts multiple joints, synovium, and cartilage
– Intense inflammatory infiltrate into synovium
-> angiogenesis -> invades and erodes cartilage and bone
-Cartilage invaded by proteolytic enzymes, cytokines (IL1andTNF) and leukocytes -> free radicals -> degrades cartilage and inhibits new cartilage formation
– Bone invasion of cytokines (IL1, TNF) boney destruction
• Extra-articular manifestations
– Fever
– Malaise
– Fatigue
– cachexia
Presentation of RA
- Slow and insidious
- Explosive, polyarticular onset
- Occasionally, limited to one to two joints
- Extra-articular presentation
- Morning stiffness, gel phenomenon
- Symmetrical joint swelling may be present
Presentation of RA 2
Usually, begins between 25 and 50 years old
Autoimmune response affecting the synovial membrane leading to joint destruction
Develops within weeks or months
Usually symmetrically, primarily affects small joints
Signs of inflammation present
Morning stiffness lasting >1 hour
Extra-articular symptoms may be present: fatigue, weight loss, anemia
More common in femalesAbsent osteophytes
Abnormal inflammatory markers usually present
Treatment of RA
- NSAIDs
- ASA and nonacetylated salicyclates
- DMARDs
- Corticosteroids
- Pain control
NSAIDs for Treatment
- Ibuprofen(Advil):800mgTID(max3200mg/day)
- Naproxen(Aleve):500mgBID(max1500 mg/day)
- Diclofenac(Zorvolex):35mgTID
- Sulindac(Clinoril):150–200mgBID(max400 mg/day)
- Meloxicam(Mobic):7.5–15mgQD(max15 mg/day)
- Piroxicam(Feldene):20mgQD(max20mg/day)
- Celecoxib(Celebrex):100–200mgBID(max400 mg/day
ASA MOA
– Rapidly metabolized to acetic acid and salicylate
– Protein bound
– Irreversibly inhibits PLT cyclooxygenase à reduces prostaglandin and thromboxane A1 synthesis
ASA Side Effects
– Many adverse s/e—particularly GI
– Contraindicated in hemophilia or other coagulation disorder
– Caution in IRF
ASA Pregnancy Category
– Pregnancy Cat C (try to avoid 3rd trimester); consider alternative with breastfeeding
ASA Dosage
– 300–600 mg QID (max 4 g/day)
Nonacetylated salicylates MOA
– Magnesium choline salicylate sodium salicylate
Nonacetylated salicylates Side effects
– similar s/e without PLT inhibition
– Reduces prostaglandin synthesis
Nonacetylated salicylates Pregnancy category
– Pregnancy C (avoid 3rd trimester); consider alternative with lactation
Disease-Modifying Antirheumatic Drugs (DMARDs)—Nonbiologics
Methotrexate (Trexall) MOA
– Inhibits inflammatory and immunoregulatory pathways, particularly pro-inflammatory cytokines linked to RA
Disease-Modifying Antirheumatic Drugs (DMARDs)—Nonbiologics
Methotrexate (Trexall) Monitoring
– LFTs, CBC assessed at baseline and q3mo; HCG (will need contraception)
– Most concerning potential s/e is hepatic toxicity
Disease-Modifying Antirheumatic Drugs (DMARDs)—Nonbiologics
Methotrexate (Trexall)
What supplement should be taken with Methotrexate?
Folic Acid
Disease-Modifying Antirheumatic Drugs (DMARDs)—Nonbiologics
Methotrexate (Trexall)
Pregnancy Category?
– Pregnancy: X lactation: unsafe
Disease-Modifying Antirheumatic Drugs (DMARDs)—Nonbiologics Hydroxychloroquine (Plaquenil)
MOA
– Possibly suppresses T lymphocytes, inhibition of leukocytes chemotaxis, stabilization of lysosomal enzymes, and trapping of free radicals
Disease-Modifying Antirheumatic Drugs (DMARDs)—Nonbiologics Hydroxychloroquine (Plaquenil)
Side Effects
– Most concerning potential s/e is ophthalmologic toxicities (rare)
Disease-Modifying Antirheumatic Drugs (DMARDs)—Nonbiologics Hydroxychloroquine (Plaquenil)
Pregnancy Category
– Pregnancy: nonteratogenic but should be avoided; safe with lactation
Disease-Modifying Antirheumatic Drugs (DMARDs)—Nonbiologics Sulfasalazine (Azulfidine)
MOA
– Suppression of T-cell responses and B-cell proliferation; inhibit release of inflammatory cytokines
Disease-Modifying Antirheumatic Drugs (DMARDs)—Nonbiologics Sulfasalazine (Azulfidine)
Caution and Side Effects
– Caution with sulfa allergy or G6PD deficiency
– Mild GI upset, rarely blood dyscrasias
Disease-Modifying Antirheumatic Drugs (DMARDs)—Nonbiologics Sulfasalazine (Azulfidine)
Monitoring
– Baseline CBC and LFTs and then ~q3mo; screening for G6PD deficiency
Disease-Modifying Antirheumatic Drugs (DMARDs)—Nonbiologics Sulfasalazine (Azulfidine)
Pregnancy Category
– Pregnancy: if benefits outweigh risk (low fetal harm); lactation: possibly unsafe; consider alternative
Disease-Modifying Antirheumatic Drugs (DMARDs)—Nonbiologics
Leflunomide (Arava)
MOA
– Has some impact on T-cell proliferation and reduced B-cell antibodies
Disease-Modifying Antirheumatic Drugs (DMARDs)—Nonbiologics
Leflunomide (Arava)
Side Effects
– Common s/e is diarrhea and elevated LFTs, leukopenia, and thrombocytopenia rarely occur
Disease-Modifying Antirheumatic Drugs (DMARDs)—Nonbiologics
Leflunomide (Arava)
Monitoring
– Baseline CBC, LFTs, and regular monitoring; HCG (contraception required)
Disease-Modifying Antirheumatic Drugs (DMARDs)—Nonbiologics
Leflunomide (Arava)
Pregnancy Category
– Pregnancy: X; lactation: possibly unsafe
List Biologics
- Tumor necrosis factor (TNF) inhibitors
- T-cell costimulatory blockade
- B-cell depletion
- Interleukin-6 (IL-6)
- Interleukin-1 (IL-1)
- Other immunomodulatory and cytotoxic agents
TNF Inhibitors
MOA
- Some fully human IgG anti-TNF monoclonal antibody or recombinant humanized antibodies with specificity for TNF
- Downregulation of macrophages and T-cell function à neutralized inflammatory effects
- Used in RA as well as other autoimmune disorders
- TNF inhibitors have a rapid onset of action—2 to 4 weeks
TNF Inhibitors:
Adverse Reactions
• Adverse reactions similar across class
– Increased risk of bacterial infections and macrophage-dependent infections (TB, fungal, and opportunistic organisms, reactivation of TB or HBV)
• Most common infections: respiratory, pneumonia, skin, and urinary tract
• DON’T HESITATE TO TREAT SUSPECTED INFECTIONS EARLY
– Increased risk of skin CA (including melanoma)
– Question of increased risk of lymphoma or solid malignancies
– Lupus or psoriasis development (rare)
– Exacerbate underlying CHF
– Development of anti-drug antibodies (~17%)
– Increased risk of GI ulcers, large bowel, and appendiceal perforation
TNF Inhibitors:
Monitoring
• Monitoring: CBC, LFTs, derm, screening TB and HBV, periodic ESR, CRP, anti-CCP
List of TNF Inhibitors
- Etanercept (Enbrel): 50 mg qwk (SQ injection)
- Infliximab (Remicade): 3mg/kg IV q8wk (infusion)
- Adalimumab (Humira): 40 mg q2wks (SQ injection)
- certolizumab pegol (Cimzia): 400 mg initial dose, 2 weeks, 4 weeks, then 200 mg qowk or q4wks (SQ injection)
- golimumab (Simponi): 50 mg q1mo (SQ injection)
T-Cell Costimulatory Blockade:
MOA
- Turn down T-cell response and decrease production of cytokines, including TNF
- Response time make take up to 3 months
T-Cell Costimulatory Blockade:
Adverse Reactions
• Adverse reactions (similar to TNF blockers) – Infections
– Caution with COPD patients – Screening for TB
T-Cell Costimulatory Blockade
Monitoring
• Monitoring: CBC, LFTs, derm, screening TB and HBV, periodic ESR, CRP, anti-CCP
B-Cell Depletion
MOA
- Depletes B-cells (removes B-cells from circulation) à decreased cytokines
- For patients that have failed TNF blockers
- Effects may take up to 3 months
B-Cell Depletion
Adverse Reactions
• Adverse reactions: – Infusion reactions (mild–severe) – Infections (similar to TNF blockers) – Reactivation of fungal infections – Progressive multifocal leukoencephalopathy (PML)—rare
B-Cell Depletion
Monitoring
• Monitoring:
– Same as TNF
– Immunizations before initiating treatment
– No live viral immunizations while on treatment
– If unsure, contact rheumatologist
B-Cell Depletion
Give Example of Medications
• Rituximab (Rituxan):
– 1000 mg IV, 2 doses 2 weeks apart – Corticosteroid IV 30 minutes prior
Interleukin-6 (IL-6) and Interleukin-1 (IL-1)
MOA
- Decreases pro-inflammatory cytokines
- Decreased production of IL-6 in synovial cells à decreased joint inflammation
- Decreased IL-1 production in joint à < cartilage degradation, < osteoclast activity, increased joint repair
Interleukin-6 (IL-6) and Interleukin-1 (IL-1)
Adverse reactions:
• Adverse reactions:
– Infection risk (same as TNF)
– IL-6: PLT, lipids, LFTs, neutropenia
– Fever, chills, body aches, headaches with infusion
Interleukin-6 (IL-6) and Interleukin-1 (IL-1)
Monitoring
• Monitoring: same as TNF, lipids (~q4–8 wks)
Interleukin-6 (IL-6) and Interleukin-1 (IL-1)
Medication Examples
• Tocilizumab (Actemra), Anakinra (Kineret)
Other Immunomodulatory and Cytotoxic Agents
Why are they not commonly used?
• Used rarely due to potential toxicity
How does Azathioprine (Imuran) MOA
can cause low blood counts, particular caution with ACE inhibitors or allopurinol à
WBC, RBC, and PLTs
Side Effects of Cyclosporine(Sandimmune, Neoral)
Side Effects
Infection and renal insufficiency, BP, numerous medication interactions
Side Effects Cyclophosphamide (Cytoxan)
serious toxicities including bone marrow suppression, infection, secondary malignancy
Side Effects d-Penicillamine (Cuprimine, Depen):
s/e severe rash and IRF, may develop lupus-like illness
Side Effects Gold
s/e rash, glomerular nephritis, immune thrombocytopenia, granulocytopenia, and aplastic anemia
Corticosteroids Pharmacodynamics
Glucocorticosteroids
Promote gluconeogenesis
Decrease glucose update
Stimulate protein catabolism
Decrease proliferation of fibroblasts in connective tissue
Inhibit immune and inflammatory systems at several sites
Promote fat deposition and lipolysis in extremities
Increase uric acid excretion and decrease calcium levels
Promote gastric acid secretion
Corticosteroids Pharmacodynamics
Feedback Activity on HPA Axis
Enhance urinary excretion
Suppress secretion of ACTH and suppression of prostaglandins
Increases osteoclast activity with decreased osteoblast activity
Inhibits somatic growth
Decreased levels of sex hormones
Modulates emotional and perceptual function
Potentiate the effects of catecholamines, thyroid and growth hormones on adipose tissues
Corticosteroids: Pharmacokinetics
- Well absorbed in jejunum (oral)
- IM/IA absorption vary by site and formulation
- Protein bound
- Metabolized in the liver
- Excreted in the kidneys
Corticosteroids: Pharmacotherapeutics
Contraindicated in active, untreated, infections and with systemic fungal infections
Can increase BP through Na+ and H2O retention with increased K+ excretion
Caution with patients that have IRF, glomerulonephritis, or chronic nephritis
Increase Ca+ excretion—caution with those at risk for OP
Caution with diabetic d/t increased gluconeogenesis
Can cause GI s/e—take with food; caution with h/o PUD; do not take with NSAIDs
Elderly patients may require lower dosing
Pediatric dosing is weight based and may cause altered growth and development
Pregnancy Category: B; lactation: appears in breast milk
Corticosteroids: Side Effects
Muscle and skin
Skin thinning, atrophy, alopecia, poor healing
Corticosteroids: Side Effects
Skeletal
OP, fractures
Corticosteroids: Side Effects
Ocular
Cataracts, glaucoma, infections
Corticosteroids: Side Effects
GI
PUD, GI upset
Corticosteroids: Side Effects
CV
HTN, edema
Corticosteroids: Side Effects
CNS
Insomnia, agitation, mood swings, severe depression, psychosis, delirium
Corticosteroids: Side Effects
Endocrine
Adrenal suppression, glucose metabolism, menstrual irregularities
Corticosteroid Drug Interactions
- NSAIDs
- ETOH
- Drugs that lower K+
- OCPs
- Specific drug interactions: Table 25-5
Prednisone Bursts
• Prednisone most commonly Rx’d
– Rx as a“burst”x5days • 40mgPOQDx5days
– Rx as a taper
• Prednisone10mg:6tabsx3days,5tabsx3days,4tabsx3 days, 3 tabs x 3 days, 2 tabs x 3 days, 1 tab x 3 days, 1⁄2 tab x 3 days, then stop
Prednisone: Monitoring
• Monitor for potential s/e • CBC • Electrolytes • Long-term treatment: – BMD – Stool for guaiac annually – Serum lipids – Eye exam
Prednisone: Patient Education
- Adverse reactions
- Need for monitoring in long-term treatment • Diet
- Vaccinations