How does this medication work? What will it do for me?

Cyclophosphamide belongs to the group of cancer-fighting medications known as antineoplastics, and specifically to the group of antineoplastics known as alkylating agents. Cyclophosphamide prevents the growth of cancer cells by interfering with the genetic material DNA, which is necessary for reproduction of cells. Because cancer cells reproduce more quickly than normal cells, they are targeted by the medication.

Cyclophosphamide is used to treat many types of cancer including cancers of the blood (e.g., leukemia, lymphoma), Hodgkin's disease, small cell lung cancer, multiple myeloma, neuroblastoma, retinoblastoma, and cancers of the soft tissues (including muscles).

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

What form(s) does this medication come in?


Each vial contains 200 mg, 500 mg, 1000 mg, or 2000 mg of cyclophosphamide. Nonmedicinal ingredients: none.


25 mg
Each round, deeply biconvex, white-to-off-white, sugar-coated tablet contains 26.7 mg of cyclophosphamide monohydrate equivalent to 25 mg anhydrous cyclophosphamide. Nonmedicinal ingredients: calcium carbonate, cellulose, dibasic calcium phosphate, gelatin, glycerin, lactose, magnesium stearate, polyethylene glycol, polysorbate, povidone, silicon dioxide, starch (corn), sucrose, talc, titanium dioxide, and wax.

50 mg
Each round, deeply biconvex, off-white, sugar-coated tablet contains 53.5 mg of cyclophosphamide monohydrate, equivalent to 50 mg of anhydrous cyclophosphamide. Nonmedicinal ingredients: calcium carbonate, cellulose, dibasic calcium phosphate, gelatin, glycerin, lactose, magnesium stearate, polyethylene glycol, polysorbate, povidone, silicon dioxide, starch (corn), sucrose, talc, titanium dioxide, and wax.

How should I use this medication?

The recommended dose of cyclophosphamide varies widely according to the specific condition being treated, the response to therapy, and other medications being used. The dose is based on body weight. It is available as an intravenous (into the vein) injection and as an oral tablet.

The intravenous form is injected into a specially prepared site on the skin. The dosing regimen for this medication varies widely. Tablets are sometimes taken on a daily basis in smaller doses, but can also be given in larger doses for a few days at a time with 2- to 4-week intervals between doses.

The intravenous form of the medication is sometimes administered twice a week, but larger doses may be given once every 3 to 4 weeks depending on the condition being treated. The intravenous form of cyclophosphamide is always given under the supervision of a doctor. Very careful handling of this medication is required. It is always given in a hospital or similar setting with access to sterile equipment for preparation.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

It is important to take this medication exactly as prescribed by your doctor.

Cyclophosphamide is excreted in urine. Your bladder will become irritated if the urine containing cyclophosphamide stays inside it for too long. It is therefore important that you drink extra fluids while taking cyclophosphamide so that extra urine is passed. The bladder should be emptied frequently so that the kidneys continue to work well. You may need to drink up to 7 to 12 cups of fluid a day.

Cyclophosphamide tablets must be taken exactly as directed by your doctor. They should be taken first thing in the morning to reduce the risk of bladder problems. Talk with your doctor about the best dosing schedule for your circumstances. Taking the medication with food can decrease stomach upset. This medication may cause nausea, vomiting and loss of appetite, but it is important that you continue to use the medicine. Do not stop taking the medicine without talking with your doctor. If you vomit shortly after taking a dose of medicine, call your doctor for instructions on whether to skip that dose or to take another dose. If you miss a dose, ask your doctor for instructions. Do not take a double dose to make up for a missed one.

As well as interfering with the genetic material DNA of cancer cells, cyclophosphamide can interfere with some of your normal cells. This can cause a number of side effects such as hair loss and mouth sores. Keep track of any side effects and report them to your doctor as suggested in the section "What side effects are possible with this medication?"

Store this medication at room temperature, protect it from light and moisture, and keep it out of the reach of children.

Do not dispose of medications in wastewater (e.g. down the sink or in the toilet) or in household garbage. Ask your pharmacist how to dispose of medications that are no longer needed or have expired.

Who should NOT take this medication?

Do not use this medication if you:

  • are allergic to cyclophosphamide or any ingredients of this medication
  • are breast-feeding
  • have inflammation of the bladder (cystitis) or urinary outflow obstructions
  • have severe liver problems
  • have severe kidney problems
  • have low platelet counts
  • have severe low white blood cell counts
  • have an active infection, particularly varicella zoster infection

What side effects are possible with this medication?

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

  • diarrhea
  • fatigue
  • feeling of being generally unwell
  • headache
  • loss of appetite
  • nausea
  • temporary loss of hair (returns after treatments end, although texture or colour may change)
  • vomiting

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

  • blood in the urine
  • burning or pain with urination
  • confusion
  • dizziness
  • fever or chills with cough or hoarseness
  • prickling, tingling, or numbness in the arms or legs
  • redness, swelling, or pain at site of injection
  • signs of anemia (low red blood cells; e.g., dizziness, pale skin, unusual tiredness or weakness, shortness of breath)
  • signs of heart failure (e.g., shortness of breath, fatigue, swelling in legs, ankles, feet)
  • signs of infection (symptoms may include fever or chills, severe diarrhea, shortness of breath, prolonged dizziness, headache, stiff neck, weight loss, or listlessness)
  • signs of kidney problems (e.g., increased urination at night, decreased urine production, blood in the urine, change of urine colour)
  • signs of liver problems (e.g., nausea, vomiting, diarrhea, loss of appetite, weight loss, yellowing of the skin or whites of the eyes, dark urine, pale stools)
  • signs of lung inflammation (e.g., darkening of the lips or fingernails, persistent cough, burning sensation in the chest)
  • skin inflammation
  • sores in mouth and on lips
  • symptoms of low blood pressure (e.g., fainting, dizziness, lightheadedness, blurred vision, increased thirst, nausea)
  • vein inflammation

Stop taking the medication and seek immediate medical attention if any of the following occur:

  • seizures
  • signs of allergic reaction (swelling of the mouth or tongue, difficulty breathing)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Are there any other precautions or warnings for this medication?

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Anemia: Cyclophosphamide may cause low levels of red blood cells. If you experience symptoms of reduced red blood cell count (anemia) such as shortness of breath, feeling unusually tired or pale skin, contact your doctor as soon as possible.

Birth control: If you or your partner is of childbearing age, talk to your doctor about appropriate birth control while using this medication. Cyclophosphamide is expected to cause birth defects, if the fetus is exposed to the medication during pregnancy. Men who are taking this medication should not father a child for at least 6 months after completing treatment with cyclophosphamide.

Bleeding: This medication can cause a reduced number of platelets in the blood, which can make it difficult to stop cuts from bleeding. If you notice any signs of bleeding, such as frequent nosebleeds, unexplained bruising, or black and tarry stools, notify your doctor as soon as possible. Your doctor will order routine blood tests to make sure potential problems are caught early.

Drowsiness/reduced alertness: Cyclophosphamide may affect the mental or physical abilities needed to drive or operate machinery. Avoid driving or performing other potentially hazardous tasks until you have determined how you are affected by this medication.

Heart problems: Inflammation of the heart and irregular heart rhythms have been reported with cyclophosphamide use. If you have heart problems, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

If you experience symptoms of irregular heartbeat or decreased heart function, such as shortness of breath, chest pain, rapid heartbeat, swollen ankles, or rapid weight gain, contact your doctor immediately.

Infection: As well as killing cancer cells, cyclophosphamide reduces the number of cells that fight infection in the body (white blood cells). If possible, avoid contact with people with contagious infections. Tell your doctor immediately if you notice signs of an infection, such as fever or chills, severe diarrhea, shortness of breath, prolonged dizziness, headache, stiff neck, weight loss, or listlessness. Your doctor will do blood tests regularly to monitor the number of specific types of blood cells in your blood.

Kidney function: The kidneys are partially responsible for removing this medication from your body. Kidney disease or reduced kidney function may cause this medication to build up in the body, causing side effects. If you have reduced kidney function or kidney disease, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Liver function: Cyclophosphamide may not be as effective when used by people with severely reduced liver function. It may also cause blockage of some of the veins in the liver, causing weight gain, enlargement of the liver, fluid build-up in the abdomen, and jaundice. If you experience any symptoms of liver problems, contact your doctor immediately.

Lung inflammation: This medication can cause severe inflammation of the lungs (pneumonitis). It has also been reported to cause blockage in the veins in the lungs. Pneumonitis has been reported to develop at any point in treatment with cyclophosphamide. Contact your doctor as soon as possible if you experience difficulty breathing, cough, a burning sensation in your chest, or symptoms of not getting enough oxygen, such as a bluish discolouration to the lips or fingernail, unusual fatigue, or weight loss.

Other cancers: The use of cyclophosphamide may increase your risk of developing other types of cancers, including bladder or urinary tract cancer, lymphoma (cancer of the lymph tissue), and thyroid cancer. Discuss any concerns you may have with your doctor.

Surgery: If you are scheduled to have surgery, inform the doctors involved in your care if you have taken cyclophosphamide within the last 10 days.

Urinary tract problems: Cyclophosphamide can cause damage to the bladder. The risk of developing bladder problems can be reduced by making sure that you consume a large amount of water. It is also important to empty your bladder (urinate) on a regular basis. If you experience symptoms of burning or pain on urination, or blood in your urine, contact your doctor as soon as possible.

Vaccines: As a result of the decreased effectiveness of the immune system, vaccines may not be as effective as they are when given to people with a strong immune system. Vaccines are generally not recommended to be given to people who are being treated with cyclophosphamide.

Pregnancy: Cyclophosphamide is expected to be harmful to the developing baby if it is used by the mother during pregnancy. It is best for both men and women to use birth control while being treated with this drug. Tell the doctor immediately if you become pregnant while using this drug. It should not be used during pregnancy unless the benefits clearly outweigh the risks.

Breast-feeding: This medication passes into breast milk. If you are a breast-feeding mother and taking cyclophosphamide, it may affect your baby. Women are advised not breast-feed while receiving cyclophosphamide treatment.

What other drugs could interact with this medication?

There may be an interaction between cyclophosphamide and any of the following:

  • allopurinol
  • "azole" antifungals (e.g., fluconazole, itraconazole, ketoconazole)
  • bacillus Calmette-Guérin (BCG)
  • carbamazepine
  • clozapine
  • denosumab
  • diuretics (e.g., hydrochlorothiazide, indapamide, metolazone)
  • efavirenz
  • filgrastim
  • fluconazole
  • HIV protease inhibitors (e.g., atazanavir, indinavir, ritonavir)
  • medications that suppress the immune system (e.g., medications used to treat conditions such as cancer, inflammatory bowel disease, multiple sclerosis, psoriasis, rheumatoid arthritis, or medications used after a transplant)
  • mifepristone
  • rifampin
  • vaccines

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

  • stop taking one of the medications,
  • change one of the medications to another,
  • change how you are taking one or both of the medications, or
  • leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.

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