Cyclophosphamide is used to treat several types of cancer.

Cyclophosphamide is also used to treat minimal change nephrotic syndrome (kidney disease) in children who cannot use other treatments or when other treatments have failed.

Cyclophosphamide may also be used for purposes not listed in this medication guide.

You should not use cyclophosphamide if you are allergic to it, or if you have:

• a bladder obstruction.

Tell your doctor if you have ever had:

• a weak immune system (caused by disease or by using certain medicines);
• an active or chronic infection (including a bladder infection);
• bladder problems;
• kidney disease (or if you are on dialysis);
• lung disease;
• heart disease;
• liver disease; or
• if you are receiving other cancer treatments or radiation.

Using cyclophosphamide may increase your risk of developing other types of cancer such as bladder cancer, thyroid cancer, or leukemia. Talk with your doctor about your specific risk.

Cyclophosphamide can harm an unborn baby if the mother or the father is using this medicine.

• If you are a woman, do not use cyclophosphamide if you are pregnant. Use effective birth control to prevent pregnancy while you are using this medicine and for at least 1 year after your last dose.
• If you are a man, use effective birth control if your sex partner is able to get pregnant. Keep using birth control for at least 4 months after your last dose.
• Tell your doctor right away if a pregnancy occurs while either the mother or the father is using cyclophosphamide.

This medicine may affect fertility (ability to have children) in both men and women. However, it is important to use birth control to prevent pregnancy because cyclophosphamide can harm an unborn baby.

Cyclophosphamide may cause you to stop having menstrual periods. Your periods should return to normal within a few months after you stop using cyclophosphamide. However, older women may have early menopause due to this effect. Talk to your doctor about this risk.

You should not breastfeed while you are using this medicine.

Use Cyclophosphamide (Cytoxan) exactly as directed on the label, or as prescribed by your doctor. Do not use in larger or smaller amounts or for longer than recommended.

Get emergency medical help if you have signs of an allergic reaction (hives, difficult breathing, swelling in your face or throat) or a severe skin reaction (fever, sore throat, burning eyes, skin pain, red or purple skin rash with blistering and peeling).

Call your doctor at once if you have:

• new worsening cough, shortness of breath, trouble breathing while lying down;
• a light-headed feeling, like you might pass out;
• pink or red urine, pain or burning when you urinate;
• bloody or tarry stools, coughing up blood or vomit that looks like coffee grounds;
• any wound that will not heal;
• heart problems--swelling, rapid weight gain, pounding heartbeats or fluttering in your chest;
• liver problems--loss of appetite, stomach pain (upper right side), bloating, dark urine, jaundice (yellowing of the skin or eyes);
• low sodium level--headache, confusion, slurred speech, severe weakness, vomiting, loss of coordination, feeling unsteady; or
• low blood cell counts--fever, chills, tiredness, blisters or ulcers in your mouth, skin sores, easy bruising, unusual bleeding, pale skin, cold hands and feet, feeling light-headed or short of breath.

Common side effects may include:

• fever, low blood cell counts;
• mouth sores;
• nausea, vomiting, diarrhea;
• hair loss; or
• missed menstrual periods.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Avoid driving or hazardous activity until you know how this medicine will affect you. Your reactions could be impaired.

Avoid being near people who are sick or have infections. Tell your doctor at once if you develop signs of infection.