Comprehensive Overview on Disease-Modifying Antirheumatic Drugs (DMARDs)

 

Disease-Modifying Antirheumatic Drugs (DMARDs)

Introduction to DMARDs

• Definition: DMARDs are a class of medications used to treat autoimmune conditions, particularly rheumatoid arthritis, by slowing disease progression.
• Types: Conventional synthetic (csDMARDs), Biologic (bDMARDs), and Targeted synthetic (tsDMARDs).

Key DMARDs Covered

• d-Penicillamine (csDMARD)
• Methotrexate (csDMARD)
• Infliximab (bDMARD)

d-Penicillamine - Mechanism of Action

• Chelates heavy metals (used in Wilson's disease)
• Suppresses T-cell activity and decreases rheumatoid factor production
• Inhibits collagen cross-linking

d-Penicillamine - Indications

• Rheumatoid arthritis (when other DMARDs are ineffective)
• Wilson's disease (primary indication)
• Cystinuria

d-Penicillamine - Adverse Effects

• Bone marrow suppression
• Proteinuria and nephrotic syndrome
• Rash, fever
• Autoimmune syndromes (e.g., myasthenia gravis)

 d-Penicillamine - Drug Interactions

• Antacids reduce absorption
• May enhance toxicity of digoxin
• Increased risk of hematologic toxicity with other immunosuppressants

Methotrexate - Mechanism of Action

• Inhibits dihydrofolate reductase
• Decreases synthesis of DNA, RNA, thymidylates, and proteins
• Anti-inflammatory via increased adenosine levels

Methotrexate - Indications

• First-line treatment for rheumatoid arthritis
• Psoriasis
• Certain cancers (at higher doses)

Methotrexate - Adverse Effects

• Hepatotoxicity
• Bone marrow suppression
• Pulmonary fibrosis
• Gastrointestinal upset

Methotrexate - Drug Interactions

• NSAIDs may increase toxicity
• Trimethoprim increases risk of marrow suppression
• Folic acid reduces side effects (often co-prescribed)

Infliximab - Mechanism of Action

• Monoclonal antibody against TNF-alpha
• Neutralizes TNF-alpha, reducing inflammation and immune response

Infliximab - Indications

• Rheumatoid arthritis (in combination with methotrexate)
• Crohn’s disease, ulcerative colitis
• Ankylosing spondylitis
• Psoriatic arthritis

Infliximab - Adverse Effects

• Infusion reactions
• Increased risk of infections (e.g., TB, fungal)
• Reactivation of hepatitis B
• Autoantibody formation

Infliximab - Drug Interactions

• Live vaccines contraindicated during treatment
• Increased immunosuppression with other biologics or immunosuppressants

Visual Aids and Case Study Discussion

• Diagrams of mechanisms (e.g., TNF-alpha pathway, folate pathway)
• Flowchart comparing side effects
• Patient case scenarios for practical understanding

Presentation for Disease-Modifying Antirheumatic Drugs (DMARDs)

                                                                        

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