RA

Etiology/pathophysiology

Treatment

Goals of therapy

Signs/symptoms

Diagnosis

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score of 6/10 on ACR/EULAR Rheumatoid Arthritis Classification Criteria

Prolonged morning stiffness (Normally >30 mins)

Changes in synovial tissue

Immune cascade dysregulation (overstimulation of innate immune system)

Primary Goal of Treatment: targeting disease remission, low disease activity ultimately aiming at enhancing quality of life.

Positive rheumatoid factor (RF) and/or anti-citrullinated peptide/protein antibody

Elevated levels of C-reactive protein (CRP) or the erythrocyte sedimentation rate (ESR)

joint involvement (at least one joint required, more joints = more points!)

The ACR as well as the EULAR guidelines suggest a treat-to-target approach when treating patients with RA rather than a nontargeted treatment approach. This approach to treatment suggests that if remission cannot be achieved, low disease activity is an acceptable alternative target. (Textbook for 630, Ch 107)

Diseases with similar clinical features have been excluded

Initial Treatment: Methotrexate (DMARD of Choice)

The duration of symptoms is more than six weeks.


Alternate: Switch to another DMARD or biologic DMARDs or combination of DMARD

EARLY GOAL: Apply aggressive treatment as early as possible as no pharmacologic or non-pharmacologic treatments can currently reverse joint damage.

Joint Swelling

Presence of warmth with or without pain

Hands, Feet, Wrists, Ankles are most commonly affected

Non-pharmacologic

Monitoring

Risk Factors

Subluxations and deformities possible with advanced disease

Etiology unknown, thought to be genetic and environmental

Decreased functionality

RA is believed to be an independent risk factor for coronary artery disease; associated with an increased risk of cardiovascular mortality

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Patient education

●Psychosocial interventions

●Rest, exercise, and physical and occupational therapy

●Nutritional and dietary counseling

●Interventions to reduce risks of cardiovascular disease, including smoking cessation and lipid control

●Screening for and treatment of osteoporosis

●Immunizations to decrease risk of infectious complications of immunosuppressive therapies

Nongenetic or environmental factors possibly associated with RA include cigarette use, coffee consumption, and obesity

Monotherapy DMARD is preferred over combination DMARD therapy

MOA

Prior to treatment initiation: 1. Baseline complete blood count, serum creatinine, aminotransferases, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) in all patients 2. Hep B and Hep C screening

ADRs

Regimen

PK/PD/PGX

autoimmune origin: results in cell proliferation, inflammation, and destruction of tissues and fluids throughout one’s own body.

Monitoring

Duration

Warnings/precautions/contraindications

Interactions

Special populations

Education/counseling

Determinants of health

T cell mediated

Assess disease activity, disease manifestations, disease progression, joint injury, disability, and complications of the disease and to monitoring for adverse effects of medications

Drug Class non-TNF biologic

Unknown in RA, but may have effect on immune function

Genetic Factors

Extra-articular manifestations: systemic signs such as fever, anorexia, malaise, weight loss, and symptoms of CV disease

Drug Class: TNFi biologics

subjective improvement of RA symptoms with respect to joint pain, swelling and tenderness, morning stiffness, and fatigue, as well as on a patient’s ability to perform activities of daily living.

GI upset

monitoring of acute phase reactants such as CRP and ESR can be useful in assessing inflammation

Thrombocytopenia

Stevens-Johnson sydrome

Hepatic fibrosis

Initial: 7.5 mg subQ once weekly

CI: in pregnancy and breastfeeding, alcoholism, alcoholic liver disease or other chronic liver disease, immunodeficiency, and preexisting hematologic disorders, such as leukopenia and thrombocytopenia

Methotrexate excretion is reduced in renal impairment and may require dose reduction or discontinuation in some cases. Excretion is also reduced in ascites or pleural effusions

adalimumab

infliximab

Prior to initiation: complete blood count (CBC) with differential, alanine transaminase (ALT), aspartate transaminase (AST), and renal function

golimumab

etanercept

Adjust dose gradually

certolizumab

Monitored every 2 to 4 weeks for 3 months after initiation or following a dose increase, then every 8 to 12 weeks during 3 to 6 months of therapy, and every 12 weeks after 6 months of therapy

abatacept

rituximab

tocilizumab

Doses > 20 mg/wk increase incidence of toxic reaction

Oral bioavailability: 23-95% (dose dependent), subQ bioavailability: 100%

tofacitinib

Lifelong

Avoid other immunosuppressants

Renal Impairment:
CrCl 10 to 50 mL/minute: Administer 50% of dose.
CrCl <10 mL/minute: Avoid use.

May take up to 6 months to feel full effect

Food reduces Cmax by 50% and delays absorption

Hepatic Impairment: Bilirubin 3.1 to 5 mg/dL or transaminases >3 times ULN: Administer 75% of dose; Bilirubin >5 mg/dL: Avoid use

Hydroxychloroquine

Methotrexate peak serum levels may be decreased if taken with food. Management: Administer without regard to food.

50% protein binding

Vd: 0.4-0.8 L/kg

May be more prone to getting infections - wash hands more

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May bleed more easily, use a soft toothbrush and electric razor

Hepatic metabolism

Avoid alcohol

PK/PK/PGX

MOA

Adverse drug reactions/allergies

Regimen

Monitoring (TVS: target concentrations, vitals/labs, and signs/symptoms) Watch the TVS!

Duration

Warnings/precautions/contraindications

Interactions (drug-drug, -food/drink, and –disease)

Special populations (age, body composition, pregnancy/lactation, and organ dysfunction)

Education/counseling

Determinants of health

leflunomide

May affect fertility

Renal excretion

Pediatric: Methotrexate doses between 100 to 500 mg/m2 may require leucovorin calcium rescue. Methotrexate doses >500 mg/m2 require leucovorin calcium rescue.

Sulfasalazine

Half-life: 3-10 hours, longer with doses > 30 mg

Tablets (Methotrexate (Anti-Rheumatic) Oral)


2.5 mg (per each): $4.05

Antimalarial: Interferes with digestive vacuole function within sensitive malarial parasites by increasing the pH and interfering with lysosomal degradation of hemoglobin; inhibits locomotion of neutrophils and chemotaxis of eosinophils; impairs complement-dependent antigen-antibody reactions.

PK/PD/PGX

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MOA

ADR/allergies

Regimen (LOT and FAR):

Onset of action: Rheumatic disease: May require several weeks to respond

Absorption: Incomplete and variable (~70% [range: 25 to 100%]) (Tett 1993)

Protein binding: ~40%, primarily albumin (Tett 1993)

Metabolism: Hepatic; metabolites include bidesethylchloroquine, desethylhydroxychloroquine, and desethylchloroquine

Half-life elimination: ~40 days

Excretion: Urine (15% to 25%

Monitoring

Duration

Warnings/Precautions/Contraindications

Interactions

Use caution with dose selection in elderly, renally impaired, hepatically impaired

CBC with differential, liver function, renal function, blood gluose

common: nausea

Geriatric: Oral: Initial: 5 to 7.5 mg per week.

liver function tests

Education/Counseling

CBC with differential

Special Population

Determinants of Health

G6PD deficiency may result in Anemia

periodic urinalysis

Pregnancy/breast feeding: fetal and infant risk cannot be ruled out

serious: retinal disorder, EPS, QTc prolongation, hypoglycemia

signs of anaphylaxis and infection

Contraindicated with hypersensitivity reactions. Warnings/precaution include cardiovascular effects, skin reactions, blood disorders, monitor for hypoglycemia, myopathy and neuromyopathy, and renal toxicity

Counsel on side effects: vertigo, tinnitus, visual field defects, N & V, fatigue, decreased appetite, headaches, dizziness, irritability

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Use in rheumatoid arthritis, polyarticular-course juvenile idiopathic arthritis, and psoriasis is contraindicated in pregnancy.

Methotrexate can cause embryo-fetal toxicity, including fetal death.

Methotrexate has the potential to cause serious adverse reactions in the breastfed infant.

This drug may change the color of urine or skin to a yellow or orange color. This is not harmful.

may cause GI upset

watch for signs and symptoms of allergic reaction (esp if have sulfa allergy)

Report symptoms of toxicity (rash, visual changes)

Mechanism Unknown; maybe chemical mediator response from leukotrienes

Take with a meal or glass of milk

stomach pain, upset stomach, vomiting, low appetite

skin rash

headache

Cost: relatively inexpensive, ~$20 for 30 tablets

Serious infections, like sepsis and pneumonia

leukopenia/thrombocytopenia

diziness

oligospermia

CNS Effects: Deaths occurred from CNS and neuromuscular changes

Oral: 200 to 400 mg daily as a single daily dose or in 2 divided doses (Kumar 2013). Note: Due to the risk of retinal toxicity, most patients should not receive a daily dose >5 mg/kg/day using actual body weight or 400 mg, whichever is lower (manufacturer’s label).

May not be in stock due to increased demand as a result of COVID

Dermatologic Reactions: SJS, exfoliative dermatitis, TEN

Lasmiditan: May increase the serum concentration of BCRP/ABCG2 Substrates.

Voxilaprevir: May increase the serum concentration of BCRP/ABCG2 Substrates

BCRP/ABCG2 substrate

Hepatic necrosis

Lifetime

Contraindication: If have hypersensitivity to med or its metabolites

No dose adjustment with hepatic or renal impairment

use with caution in hepatic and renal patients

Do not take antacids or kaolin within 4 hours of this drug

Onset of action: >4 weeks

Absorption: oral <15% as parent drug

Max dose: 3g/day for adults

Initial dose: 0.5g PO daily or 1g/day in 2 divided doses; increase dose to 3g/day with careful monitoring (if inadequate response in 12 weeks)

not preferred in pregnancy (crosses the placenta)

Protein binding: >99% to albumin

Maintenance dose: 2g/day in 2 divided doses

Distribution: Vd: 7.5 ± 1.6 L

Indefinite

Low cost: $13 for 30 tablets

Metabolism: Via colonic intestinal flora to sulfapyridine and 5-aminosalicylic acid (5-ASA). Following absorption, sulfapyridine undergoes acetylation to form AcSP and ring hydroxylation while 5-ASA undergoes N-acetylation (non-acetylation phenotype dependent process); rate of metabolism via acetylation dependent on acetylation phenotype

Bioavailability: <15%

Half-life elimination: 7.6 ± 3.4 hours (prolonged in elderly patients)

Time to peak: 3 to 12 hours (mean: 6 hours)

Excretion: Primarily urine (as unchanged drug, conjugates, and acetylated metabolites); feces (small amounts)