Dermatologists are often required to prescribe immunosuppressive agents for
the treatment of serious and recalcitrant dematoses. Azathioprine, cyclophosphamide,
methotrexate, and cyclosporine are the immunosuppressive agents most commonly used
by dermatologists. The immunosuppressive drugs act by a variety of mechanisms. In
general, the precise mechanisms responsible for most therapeutic benefits observed with
these agents are understood only partially. Unlike biologic agents that selectively inhibit
a proinflammatory cytokine and/or block its receptor, the immunosuppressive drugs
interfere with combinations of critical pathways in the inflammatory cascade. Among
the immunosuppressive drugs, several are "cytotoxic", causing either cell death or
impaired proliferation; such drugs include cyclophosphamide, chlorambucil,
methotrexate, and azathioprine. Other drugs suppress the immune system by inhibiting
the proliferation or function of lymphocytes. This class includes drugs such as
cyclosporine and tacrolimus, which specifically target calcineurin and thereby inhibit
the production of interleukin-2 by activated T-lymphocytes. Others prevent lymphocyte
proliferation by inhibiting nucleotide synthesis, for example, mycophenolate mofetil
blocks the synthesis of purine. Finally glucocorticoids have many effects upon innate
and acquired immunity. Familiarity with disease-specific clinical efficacy, side-effect
profile, and dosage allows the successful and judicious use of these drugs in
dermatologic disorders. This chapter summarizes the characteristics of systemic
immunosuppressive agents commonly used in dermatology.
Keywords: Cyclosporine, methotrexate, cyclophosphamide, azathioprine, mofetil
mycofenolate, intravenous immunoglobulins, immunosupressive agents, cyclosporine,
methotrexate, cyclophosphamide, azathioprine, mofetil mycofenolate, intravenous
immunoglobulins, administration, oral, infusions, parenteral, skin and connective
tissue diseases, skin.
