Table 4.
Drugs | Usual dosage | Mechanism of action | Common Toxicities | Corticosteroid sparing potential | Corticosteroid replacing potential | Comments |
---|---|---|---|---|---|---|
Adalimumab | 40 units every week SC. Consider initial higher loading dosages. | TNF-α antagonism | Allergic reaction, increased risk of infection especially TB, CHF, possible increased risk of malignancy, injection site reaction | +++ | ++ | Less immunogenic than infliximab, screening for latent TB is required. |
Azathioprine | 50–200 mg daily | As a purine analogue, inhibits purine synthesis necessary for T-, B- cell proliferation | Leukopenia, hepatotoxicity, risk of infection, skin cancer | +++ | + | Monitor CBC & LFT; check TPMT level at initiation (controversial)*. |
Infliximab | 3–5 mg/kg initially & at 2 weeks and 6 weeks, then every 4–6 weeks IV | TNF-α antagonism | Allergic reaction, increased risk of infection especially TB, CHF, possible increased risk of malignancy | +++ | ++ | Autoantibodies may develop with chronic use that may reduce efficacy, screening for latent TB is required. |
Leflunomide | 10–20 mg daily | Inhibits COX- 2 enzyme; DHODH inhibition affecting pyrimidine synthesis | Leukopenia, hepatotoxicity, risk of infection, skin rash, fatigue, pneumonitis, peripheral neuropathy | +++ | + | Monitor CBC & LFT; because of a long circulating half-life, leflunomide toxicity may require cholestyramine to quickly remove the drug and its metabolites. |
Methotrexate | 10–15 mg weekly | Inhibits the metabolism of folic acid in purine and pyrimidine synthesis | GI intolerance, oral ulcers, hepatotoxicity, leukopenia, fatigue, risk of infection, pneumonitis | +++ | + | Teratogenic; folate supplementation is recommended; monitor CBC & LFT. |
Mycophenolate | 3000–1500 daily | Inhibits de novo guanosine nucleotide synthesis and has a cytostatic effect on T and B cell proliferation | Leukopenia, risk of infection, lymphoproliferative disorders, skin cancer | +/− | +/− | Very limited data supporting both effectiveness and safety |
Repository Corticotropin (RCI) | 40–80 unit SC twice weekly | Stimulates ACTH secretion | Mood change, elevated HBA1c, bruising | +++ | +++ | |
Rituximab | 375 mg/m2 IV every 2 weeks | Monoclonal antibody against CD20 surface antigen of B-lymphocytes | Transfusion reaction, pancytopenia, opportunistic infection, fatigue, headache, neuropathy | + | + |
CBC: complete blood count; LFT: liver function test; DHODH: dihydroorotate dehydrogenase; COX 2: cyclooxygenase-2; TPMT: Thiopurine; IV: intravenous: SC: subcutaneous; TB: Tuberculosis; CHF: congestive heart failure; GI: gastrointestinal; +++: very good; ++: good; +: fair