Safety of Cyclophosphamide Therapy in Autoimmune Rheumatic Diseases

Cyclophosphamide (CYC) is one of the most potent antineoplastic and immunosuppressant agents. It is used as a drug of choice in many organ-threatening manifestations of systemic autoimmune rheumatic diseases (AIRDs) such as lupus nephritis, antineutrophil cytoplasmic antibody-associated vasculitis, classical polyarteritis nodosa, and myositis. It is also used in connective tissue disease-related interstitial lung disease and Behcet's disease. However, its use may be limited by the toxicities including its adverse effects on gonads in the childbearing age group, severe infections, hemorrhagic cystitis, and malignancies associated with prolonged usage. As a result, mycophenolate, azathioprine, and rituximab have gained popularity over CYC as an induction and maintenance agent in many AIRDs. However, in the event of failure of aforementioned agents in aggressive rheumatic diseases or in a resource-limited setting, the usage of CYC continues to be a useful therapeutic strategy. In this review, we have appraised the adverse effects of CYC therapy in AIRDs which would help clinicians in taking informed decisions regarding CYC usage.