PDR Health


What is Cytoxan?

Cytoxan (cyclophosphamide) is a cancer medication that interferes with the growth and spread of cancer cells in the body.

Cytoxan is used to treat several types of cancer, including leukemia, lymphoma, multiple myeloma, ovarian cancer, breast cancer, and bladder cancer.

Health Benefits

Cytoxan has been shown to be effective in the treatment of several types of cancer.

In a study of women with ovarian cancer, Cytoxan was found to reduce the risk of the cancer returning by 50%.

In another study, Cytoxan was found to be effective in the treatment of bladder cancer.

Side Effects

Cytoxan can cause serious side effects, including:

nausea and vomiting



stomach pain or cramping

loss of appetite or weight loss

weakness or fatigue tiredness




blurred vision

ringin ears



body aches

Cytoxan can also cause less serious side effects, including:

mild nausea or vomiting

mild diarrhea or constipation

mild stomach pain or cramping

mild headache or dizziness

mild drowsiness or tiredness

If you experience any of the following serious side effects, stop taking Cytoxan and seek emergency medical attention or contact your doctor immediately: an allergic reaction (difficulty breathing; closing of your throat; swelling of your lips, tongue, or face; hives); severe nausea, vomiting,or diarrhea; bloody stool; coughing up blood; mouth sores; skin sores; white patches in your mouth or throat.


Cytoxan is available in the following dosages:

25 mg, 50 mg, 100 mg, 150 mg, 200 mg tablets

5 mg/mL injection solution

The recommended dosage of Cytoxan for ovarian cancer is 100-200 mg daily. The recommended dosage for bladder cancer is 50-100 mg daily.

To reduce the risk of side effects, your doctor may start you on a low dose of Cytoxan and gradually increase your dose. Follow your doctor’s instructions carefully. Do not take more or less Cytoxan than prescribed by your doctor.

Cyclophosphamide can be given orally (by mouth) or intravenously (into a vein).


Cytoxan can interact with other medications, herbs, or vitamins you might be taking. This could increase your risk of side effects or cause your medications to not work as well. To avoid drug interactions, be sure to tell your doctor about all the drugs, herbs, and vitamins you are taking. Do not take Cytoxan if you are taking the following medications:

Probenecid (Benemid)

Sulfinpyrazone (Anturane)

Tolbutamide (Orinase)

Cytoxan can also interact with certain foods. Therefore, it is important to talk to your doctor about any food allergies or sensitivities you may have before taking Cytoxan.

Pregnancy and Cytoxan

Cytoxan is classified as a Pregnancy Category D drug, which means it may be harmful to a developing fetus. If you are pregnant or planning to become pregnant, be sure to talk to your doctor before taking Cytoxan.

It is not known whether Cytoxan passes into breast milk. Therefore, if you are breastfeeding or planning to breastfeed, be sure to talk to your doctor before taking Cytoxan.

Mechanism of Action

Cytoxan works by inhibiting the growth of cancer cells and by preventing them from spreading. Cytoxan also works by damaging the DNA of cancer cells, which prevents them from reproducing.

Cytoxan belongs to a class of drugs known as alkylating agents. Alkylating agents work by binding to DNA and causing breaks in the DNA strands. This ultimately leads to the death of the cancer cell.


Cytoxan is rapidly absorbed from the gastrointestinal tract and reaches peak concentrations in 1-2 hours. The half-life of Cytoxan is 4-6 hours.


Cytoxan should be stored at room temperature, between 59 and 86 degrees F (15 and 30 degrees C). Store away from heat, moisture, and light. Do not store in the bathroom. Keep Cytoxan out of the reach of children and away from pets.

Alternatives to Cytoxan

There are several alternatives to Cytoxan, including:

Bevacizumab (Avastin)

Capecitabine (Xeloda)

Carboplatin (Paraplatin)

Cisplatin (Platinol)

Docetaxel (Taxotere)

Epirubicin (Ellence)