Drug Class
Cytotoxic/Immunosuppressive-drugs of this class suppress the natural immune system.
Mechanism of Action
Cytotoxic drugs suppress B and T lymphocyte activity and total number. The B and T lymphocytes are involved in the autoimmune disease process.
Dosage Regimens
| Condition | Information | Oral Dosage | Intravenous Dosage |
| Wegener’s granulomatosis, Lupus nephritis, other forms of systemic vasculitis | Effective in combination with steroids such as prednisone | 2 milligrams/kilogram Cytoxan + 1 milligram/kilogram Prednisone daily
(rapidly progressive disease may require 4-5 mg/kg of cyclophosphamide daily) |
500-1000 mg/mevery month for 6 months |
Contraindications
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DO NOT take this medication if you are allergic to cyclophosphamide products or if you have a low white blood cell count.
Common Side Effects
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Hair loss occurs in 40-60% of all patients.
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Nausea and vomiting
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Nail damage such as hyperpigmentation and pigmented bands
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Decrease in the number of circulating white blood cells (leukopenia) - may increase susceptibility to infection
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Decrease in platelet count (thrombocytopenia) – may increase risk of bleeding
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Decrease in red-blood cell count – may result in anemia
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Bladder cancer is associated with long-term therapy (2 to 10 years)
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Absence of menstrual periods (Amenorrhea) in females
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Gonadal damage (damage to the ovaries or testes) in males and in females
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Sexual dysfunction and testicular hypofunction also may occur.
Drug Interactions
| Drug Name | Interaction |
| Allopurinol (Zyloprim®) | Cyclophosphamide blood concentrations can increase. This may cause patients to be more susceptible to cyclophosphamide’s side effects. Allopurinol (in addition to cyclophosphamide) may cause bone marrow suppression, nausea and vomiting. |
| Anesthetic drugs (succinylcholine, nitrous oxide, halothane) | Cyclophosphamide may prolong the effects of anesthetic drugs. |
| Cimetidine | Increases blood concentrations of cyclophosphamide. |
| Cyclosporine (Neoral®, Sandimmune®, Gengraff® | Cyclosporine blood concentrations can decrease leading to reduced efficacy. |
| Phenobarbital, Phenytoin (Dilantin®) | Decreases blood concentrations of cyclophosphamide |
Patient Instructions
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DO NOT use this medication if you are allergic to it, pregnant or breastfeeding.
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This medicine may be taken with food to avoid stomach upset. Plenty of fluids should be consumed while taking this medication to keep the kidneys working properly and prevent bladder accumulation.
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If you forget to take your medicine or miss a dose, take it as soon as possible. If it is close to the time for your next dose, skip the missed dose and take the medicine on schedule. Do NOT take extra medicine to make up for missed doses.
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Store this medication at room temperature (25 degrees Celsius) and keep it away from heat, moisture and direct light.
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Females should use two forms of birth control to avoid pregnancy while on this medication because it can cause serious birth defects. Such contraception and caution should be continued for at least six months after treatment ends.
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Watch for the following symptoms and call your doctor immediately if you experience ANY of them: itching, swelling in the face or hands, blood in urine or stool, painful urination and discoloration, fever, chills, unusual bleeding, bruising or weakness, yellow eyes or skin.
