While some of the side effects of Imuran (azathioprine), Cytoxan (cyclophosphamide) and other immunosuppressive and cytotoxic drugs are noted above, they are generally reversible by either reducing the dosage or stopping the medication. Although immunosuppressive drugs can have serious side effects, they can be of great value in the treatment of lupus. They can help to prolong life, preserve kidney function, reduce symptoms, and sometimes may serve to put the disease into remission. These drugs help to reduce symptoms and damage to vital organs, such as the kidney, until a natural remission occurs. They sometimes help to achieve a remission earlier.
Immunosuppressive and cytotoxic drugs are sometimes used in the treatment of systemic lupus erythematosus (SLE) for two major reasons. First, they are potent drugs which help to reduce disease activity in major organs such as the kidney. Second, they may reduce or sometimes eliminate the need for steroids (cortisone derivatives such as prednisone). Steroids used alone to treat major organ involvement must sometimes be given in high doses. This increases the risk of both short-term and long-term side effects, which may sometimes be worse than the disease itself. Immunosuppressive drugs can be used either in addition to, or instead of, steroids or to lower the amount of steroid needed and often spare the patient the undesirable side effects of steroid therapy.
Imuran is also used to treat lupoid hepatitis, rheumatoid arthritis and other autoimmune disorders, and to reduce the amount of steroids given.
Patients receiving treatment with Cytoxan have an increased risk of developing malignancies including leukemia, bladder cancer, and other tumors. Cytoxan may also cause temporary or permanent sterility in both women and men, preventing them from having children. It may also cause damage to a developing fetus if a woman gets pregnant unintentionally while being treated with the drug. Use of Cytoxan may cause bleeding from the bladder, but this usually can be prevented by drinking large amounts of water. Cytoxan also predisposes a patient to develop shingles, which is a painful, blistering skin condition. It can cause hair loss. Like Imuran, use of Cytoxan may predispose a patient to develop unusual infections, particularly when it is used in combination with high doses of steroids.
A typical daily dose of Imuran or Cytoxan is 125 to 150 milligrams (mg) a day given orally. A low dose is 75 mg or less. Cytoxan should be taken in the morning with fluid and should not be taken at night, when fluid intake is low. Cytoxan and Imuran are not used together except in certain experimental conditions. Cytoxan (but not Imuran) can be given at a much higher dose intravenously on a monthly basis. This may be quite effective for severe kidney disease and may help to avoid some of the side effects that occur with daily oral dosages of this drug.
Methotrexate is usually given orally once a week, although it may also be given by injection. The dosage is generally 7.5 to 20 milligrams per week. Methotrexate is well tolerated by most patients. Its use in lupus has not been thoroughly tested, but it is given quite commonly for rheumatoid arthritis and has been shown to produce improvement of joint pain and stiffness. It does not predispose a patient to develop malignancies. However, liver disease and lung reactions can occasionally occur with the use of methotrexate and it can be sun sensitizing. Dosage may need to be decreased if kidney disease is present. Blood counts should also be taken each month in patients receiving this drug and dosage modified if side effects are detected.
Therefore, it is important to assess the beneficial effects as well as the risks involved in cytotoxic drug therapy. Doctors use the term "risk-benefit ratio" to describe the comparison of side effects to beneficial effects of medications. While these drugs are not FDA-approved, they are commonly used and accepted as standard practice. People with lupus should discuss the riskªbenefit ratio of these medications with their physician.