Using Cyclophosphamide and Methotrexate for Wegener's
Cyclophosphamide (Cytoxan®) is the most commonly used cytotoxic drug used to treat Wegener's granulomatosis. People with Wegener's granulomatosis take cyclophosphamide once a day by mouth and must take the drug all at once in the morning, followed by drinking a large amount of liquid. Although the first dose of cyclophosphamide is based on the person's weight and kidney function, the doctor may adjust the dosage based on blood counts, which are monitored closely to be sure that the white blood cell count is maintained at a safe level.
In the early days of treating people with Wegener's granulomatosis, cyclophosphamide was continued for a full year beyond that point at which the Wegener's granulomatosis was in remission. The dose of cyclophosphamide was then decreased gradually and eventually stopped. In more recent approaches to Wegener's granulomatosis treatment, however, cyclophosphamide is given until remission and then switched to another medicine, such as methotrexate or azathioprine.
Cyclophosphamide is a powerful medicine that keeps the immune system from working normally. Doctors monitor patients with Wegener's granulomatosis carefully and perform frequent blood tests.
In people with Wegener's granulomatosis, cyclophosphamide can cause an increased risk of:
- Bone marrow suppression (lowering of blood counts)
- Hemorrhagic cystitis (bleeding from the bladder)
- Bladder cancer
- Other serious side effects.
In people with active but not immediately threatening Wegener's granulomatosis, methotrexate has been used in combination with prednisone to bring about remission. It also is used to maintain remission after a person has initially received cyclophosphamide. People with Wegener's granulomatosis usually take methotrexate for one to two years, after which time, if the disease continues to stay in remission, the methotrexate is decreased and stopped.
For people with Wegener's granulomatosis, methotrexate is given once a week, usually by mouth, but occasionally as an injection under the skin or in the muscle. People taking methotrexate need to have regular blood work to monitor their response and to watch for side effects.
The side effects of methotrexate include:
- Lowering of the blood counts
- Soreness and ulceration of the inside of the mouth
- Irritation of the lungs (pneumonitis)
- Inflammation and scarring of the liver.
People taking methotrexate cannot drink alcoholic beverages. Methotrexate cannot be given to people who have poor kidney function or who have underlying liver disease, such as hepatitis.