Cyclophosphamide in lupus nephritis.

Although not licensed for systemic lupus erythematosus (SLE), cyclophosphamide (CYC) has become over the last two decades the most widely prescribed cytotoxic drug for lupus nephritis (LN). A PubMed search using 'lupus nephritis and cyclophosphamide' as key words identifies not less than 454 papers on the topic. This should, however, not disguise the fact that its use is still controversial and that many issues remain debated, such as the timing and length of treatment, the route of administration and the ideal dosage. In this review, the different CYC regimes on the basis of the results of prospective randomized trials performed in LN patients is discussed.