Medication Summary
The goals of pharmacotherapy are to reduce morbidity and to prevent complications. Agents used to treat Felty syndrome (FS) include immunosuppressive agents and hematopoietic growth factors.
Immunosuppressants
Class Summary
Immunosuppressive agents inhibit key factors in the immune system responsible for immune reactions.
Methotrexate (Rheumatrex, Trexall)
Methotrexate is an antineoplastic agent that is immunosuppressive at lower doses. It is very effective in treating rheumatoid arthritis (RA). Antirheumatic effects may take several weeks to become apparent. Its mechanism of action in treatment of inflammatory disorders is unknown; it may affect immune function. Methotrexate ameliorates symptoms of inflammation (eg, pain, swelling, and stiffness). Succinct guidelines for use and monitoring are available from the American College of Rheumatology.
Cyclophosphamide
Cyclophosphamide is an antineoplastic alkylating agent and immunosuppressive agent. It reduces the numbers of B and T cells and increases the risk of infection.
Hematopoietic Growth Factors
Class Summary
CSFs stimulate production, maturation, and activation of neutrophils and increase migration and cytotoxicity of neutrophils.
Filgrastim (Neupogen)
A solid record of success is emerging with the use of CSFs in patients with FS and infections that are not responding to antibiotics alone. Most experience has been with the use of granulocyte CSF (G-CSF).
Sargramostim (Leukine)
Granulocyte-macrophage CSF (GM-CSF) stimulates division and maturation of earlier myeloid and macrophage precursor cells. It reportedly increases granulocytes in 48-91% of patients.
Antineoplastics, Monoclonal Antibody
Class Summary
Monoclonal antibodies are genetically engineered chimeric murine-human immunoglobulins directed against proteins involved in cell cycle initiation.
Rituximab (Rituxan)
Rituximab is a genetically engineered chimeric murine/human monoclonal antibody (immunoglobulin G1 [IgG1] kappa) against CD20 antigen on the surface of normal and malignant B cells. It is not to be administered as an intravenous bolus. Current data suggest that rituximab should be considered a second-line therapy in patients with refractory FS.
