CYCLOPHOSPHAMIDE IS an alkylating agent that suppresses the number and function of T and B lymphocytes, thereby reducing autoantibody production.1,2 The use of cyclophosphamide in dermatology is reserved for potentially life-threatening and therapeutically resistant diseases, such as pemphigus vulgaris and cicatricial pemphigoid, as well as severe forms of systemic lupus, systemic necrotizing vasculitis, Still disease, Behçet disease, multicentric reticulohistiocytosis, relapsing polychondritis, and pyoderma gangrenosum.3-5 The well-known toxic effects associated with cyclophosphamide use, including infections, cancer, and premature ovarian failure, make the decision to use the drug difficult. Generally, cyclophosphamide is used only after therapeutic failure of glucocorticoids, often in combination with less toxic immunosuppressives. In the case of cicatricial pemphigoid, permanent blindness and the relatively unresponsive nature of ocular or mucosal forms of the disease to glucocorticoids and other immunosuppressive drugs make the early use of cyclophosphamide a therapeutic necessity for many patients.4
Currently, there are 2 widely used methods for administering cyclophosphamide: daily oral administration vs intravenous injection once a month or less often