Cyclophosphamide (intravenous, oral)

Available as a tablet or an injection, Cyclophosphamide works by impacting the growth of cancer cells and preventing them from multiplying.


Cyclophosphamide is a prescription-only medication that is used to treat certain types of cancer, including blood, ovarian, breast cancer, lymph system and nerve cancer. The drug can also be used to treat several other conditions, including a type of eye cancer usually diagnosed in children (retinoblastoma), skin tumors (mycosis fungoides) and bone marrow cancer (multiple myeloma).

Cyclophosphamide is part of a family of drugs called alkylating agents. These drugs work by impacting the growth of cancer cells, helping the body to destroy those that exist and preventing the growth of new ones.

Cancer is a serious condition that leads to deterioration and death if not treated. The disease can affect various parts of the body and happens when cells divide uncontrollably to form tumors (which are lumps of tissue under the skin). There are more than 200 forms of cancer, of which more than 1.5 million people in the United States are diagnosed each year, causing more than 575,000 deaths. There is no cure for cancer, and the disease is one of the largest causes of death across the world. However, there are treatments that can be offered to patients in the earlier stages of the disease that can suppress the condition. If it is kept to one area, cancer cells can be killed, or the area of growth can be removed depending on the location. There are also treatments that can prolong the life of patients for whom the disease has progressed.

Unfortunately, Cyclophosphamide cannot tell the difference between cancerous cells and healthy cells. Therefore, it can also destroy healthy cells, leading to side effects for the patient as a result of a weakened immune system. Side effects that are experienced when taking a course of Cyclophosphamide can be serious and therefore the patient should be monitored closely throughout the treatment. He or she should also ensure that unpleasant symptoms are reported to a doctor. Failure to report or detect serious side effects could lead to life-threatening consequences and health complications.

The medication is also sold and marketed under two brand names in the United States, Cytoxan and Cytoxan Lyophilized “ one being for the oral route and the other for the intravenous route.

Type Of Medication

  • Tablet
  • Powder for solution
  • Capsule

Conditions Treated

Side Effects

As with any cancer medication, Cyclophosphamide is a strong and potent treatment and, as the drug kills good cells as well as bad, it can create some severe side effects.

Some side effects are common and are not usually a cause for concern. There may be other medications that can help to alleviate uncomfortable reactions to the drug. Common side effects, which can occur in up to 30% of patients are below:

  • Persistent cough or hoarse voice
  • Chills
  • High fever, or flu-like symptoms
  • Missed periods (in women)
  • Urination that is painful, difficult or fragmented

More serious, but fairly common, side effects are below. These may be more common in those that are undergoing a longer course of treatment, or are taking a higher dose. These side effects should be carefully monitored and can be treated to ease any pain:

  • Blood in the urine
  • Dizziness or confusion
  • Pain in the joints
  • Change in heartbeat, for example, an increase or irregularities
  • Difficulty in catching a breath or shortness of breath, even after only mild exertion
  • Agitation
  • Swelling in the feet, lower legs or hands
  • Excessive tiredness or drowsiness

Some patients may also suffer rarer side effects. These may or may not be a cause for concern, but should be reported to a healthcare professional regardless:

  • Black stools
  • Tarriness in the stools
  • Skin rashes or red pin-like spots on the skin
  • Shortness of breath that can come on suddenly
  • Unusual bruising or bleeding
  • Sores in and around the mouth, such as mouth ulcers, white spots, and cold sores
  • Redness, pain, soreness or swelling at the site of injection (intravenous version only)
  • Increased thirst
  • Jaundice (yellowing of the skin or eyes)
  • Wounds that do not heal properly

Some side effects that can be experienced by patients do not usually require medical treatment, but they may seem worrying for the patient. As the body adjusts to having the medicine in its system, the side effects should gradually subside. These side effects are:

  • Darkening of the skin (not related to sun exposure)
  • Darkening of the fingernails
  • Lack of appetite
  • Nausea or vomiting
  • Hair loss
  • Headache
  • Hot flushing
  • Redness in the face
  • Diarrhea
  • Swelling of the lips and surrounding area
  • Pain in the stomach
  • Excessive sweating
  • Hives or itchy skin

Patients taking this drug can also be vulnerable to developing infections, including viral, fungal and bacterial. As the immune system is weaker due to many healthy white blood cells having been destroyed, the body will be less able to fight infections. Therefore, even small infections such as a common cold can become dangerous and even life-threatening. Patients should report signs of infection as soon as they notice them.


Cyclophosphamide comes with two options for administration “ orally as a tablet, or intravenous as an injection. The route of administration will depend on the severity of the condition of the patient, as well as a number of other medical factors.

The dosage will also depend on the type of cancer that the patient is suffering from; there is generally a different dosage for each cancer:

- Ovarian cancer - 600 mg, m2 on first day of treatment via injection. The drug should be given in combination with carboplatin or cisplatin. The cycle should be repeated every 28 days
- Multiple myelomas - 10 mg, kg via intravenous route on day one

For children, the dosage is usually adjusted. For malignant disease, it is as follows:

Intravenous: The initial dose for patients that do not have a hematologic deficiency is 40 to 50 mg/kg. This treatment is normally divided over between two and five days. Another option is to give 10 to 15 mg / 7 kg every seven to ten days, or three to five mg/kg of body weight two times per week.
Oral: children should be prescribed between one and eight mg/kg/day for initial and maintenance doses

Patients that are taking this medication should be closely monitored throughout each treatment of chemotherapy and dosages should not be missed. Each injection should be administered by a trained medical professional that has experience in managing cancers.

Major drug interactions

Before taking Cyclophosphamide, you should have a full conversation with your doctor about the suitability of the drug for your health. There are a number of reasons why Cyclophosphamide may not be the right treatment for you, for instance, if you are taking and rely on certain other medications. Some medications can interact with others, causing a reaction and side effects for the patient.

Not all drug interactions mean that you can't take the medications at the same time; it may just mean that your treatment will need to be slightly altered. Drug interactions are grouped into three categories “ minor, moderate and major. Minor interactions can usually be taken together, but there may be precautions that you should take, or the doctor may wish to alter your dose. Moderate interactions are not usually suitable for taking together. Major interactions should not be taken at the same time, as the health risk is thought to outweigh the potential benefit to health.

There are almost 1,000 medicines and substances that react with Cyclophosphamide on some level. Of these, almost 50 of them can cause major interactions. Have a browse of the list of major interactive drugs below, and if you are taking any of these drugs, you should discuss options with your doctor:

  • ACAM2000 (smallpox vaccine)
  • AccessPak for HIV PEP Expanded with Kaletra (emtricitabine, lopinavir, ritonavir, tenofovir)
  • AccessPak for HIV PEP Expanded with Viracept (emtricitabine, nelfinavir, tenofovir)
  • adalimumab
  • Amjevita (adalimumab)
  • Arava (leflunomide)
  • Atripla (efavirenz, emtricitabine, tenofovir)
  • Attenuvax (measles virus vaccine)
  • Aubagio (teriflunomide)
  • bcg
  • Biavax II (mumps virus vaccine, rubella virus vaccine)
  • certolizumab
  • cidofovir
  • Cimzia (certolizumab)
  • Clopine (clozapine)
  • clozapine
  • Clozapine Synthon (clozapine)
  • Clozaril (clozapine)
  • Cyltezo (adalimumab)
  • deferiprone
  • Denzapine (clozapine)
  • Dryvax (smallpox vaccine)
  • efavirenz, emtricitabine, tenofovir
  • emtricitabine, lopinavir, ritonavir, tenofovir
  • emtricitabine, nelfinavir, tenofovir
  • Enbrel (etanercept)
  • Erelzi (etanercept)
  • etanercept
  • FazaClo (clozapine)
  • Ferriprox (deferiprone)
  • fingolimod
  • FluMist (influenza virus vaccine, live, trivalent)
  • FluMist Quadrivalent (influenza virus vaccine, live, trivalent)
  • Gilenya (fingolimod)
  • golimumab
  • Humira (adalimumab)
  • Imlygic (talimogene laherparepvec)
  • Inflectra (infliximab)
  • infliximab
  • influenza virus vaccine, h1n1, live
  • influenza virus vaccine, live, trivalent
  • leflunomide
  • M-M-R II (measles virus vaccine, mumps virus vaccine, rubella virus vaccine)
  • M-R-Vax II (measles virus vaccine, rubella virus vaccine)
  • measles virus vaccine
  • measles virus vaccine, mumps virus vaccine, rubella virus vaccine
  • measles virus vaccine, mumps virus vaccine, rubella virus vaccine, varicella virus vaccine
  • measles virus vaccine, rubella virus vaccine
  • Meruvax II (rubella virus vaccine)
  • mumps virus vaccine
  • mumps virus vaccine, rubella virus vaccine
  • Mumpsvax (mumps virus vaccine)
  • nalidixic acid
  • natalizumab
  • NegGram (nalidixic acid)
  • Orimune (poliovirus vaccine, live, trivalent)
  • poliovirus vaccine, live, trivalent
  • ProQuad (measles virus vaccine, mumps virus vaccine, rubella virus vaccine, varicella virus vaccine)
  • Quadramet (samarium sm 153 lexidronam)
  • Remicade (infliximab)
  • Renflexis (infliximab)
  • Rotarix (rotavirus vaccine)
  • RotaShield (rotavirus vaccine)
  • RotaTeq (rotavirus vaccine)
  • rotavirus vaccine
  • rubella virus vaccine
  • samarium sm 153 lexidronam
  • Simponi (golimumab)
  • Simponi Aria (golimumab)
  • smallpox vaccine
  • Stamaril (yellow fever vaccine)
  • talimogene laherparepvec
  • Tepadina (thiotepa)
  • teriflunomide
  • thalidomide
  • Thalomid (thalidomide)
  • TheraCys (bcg)
  • Thioplex (thiotepa)
  • thiotepa
  • Tice BCG (bcg)
  • Tice BCG Vaccine (bcg)
  • tofacitinib
  • typhoid vaccine, live
  • Tysabri (natalizumab)
  • varicella virus vaccine
  • Varivax (varicella virus vaccine)
  • Versacloz (clozapine)
  • Vistide (cidofovir)
  • Vivotif Berna (typhoid vaccine, live)
  • Vivotif Berna Vaccine (typhoid vaccine, live)
  • Xeljanz (tofacitinib)
  • Xeljanz XR (tofacitinib)
  • yellow fever vaccine
  • YF-Vax (yellow fever vaccine)
  • Zaponex (clozapine)
  • Zostavax (zoster vaccine live)
  • zoster vaccine live


There are various health warnings that people taking Cyclophosphamide should be aware of. The medicine has interactions with several diseases and conditions and is therefore not suitable for you if you are suffering from any of these. You should consult with a doctor if you are suffering from any of the following, as you may need an adjusted dose, closer monitoring or another treatment altogether:

  • Severe myelosuppression
  • Hypersensitivity

This medication may also lead to heart failure, pulmonary fibrosis, and infertility in male patients.

Use the medication with extreme caution if you suffer from any of the following conditions or diseases. The medication can make your conditions worse:

Other chemotherapy or radiotherapy

This medication should be used with caution in any patients that have recently undergone a course of radiation therapy or chemotherapy. These patients may already have weakened immune systems and other complications that may have arisen as a result of their previous treatments; they may, therefore, be less likely to cope with the side effects of Cyclophosphamide and could even be more prone to infections.


Cyclophosphamide should not be used during pregnancy except in emergencies that are considered to be life-threatening. Medical studies have found there to be a high risk of harm to the fetus when the drug is taken during a human pregnancy. It is also unsuitable for use during breastfeeding. If no other alternative treatment is an option for a breast-feeding mother, the mother should stop breast-feeding and the infant should instant be fed using formula milk. Cyclophosphamide gets into the breast milk and therefore can be consumed by a nursing baby, causing potentially dangerous side effects for the infant.


Oral tablets should be kept at room temperature, between 20 and 25 degrees centigrade. They should be stored away from direct sunlight and should not be kept close to radiators. It is very important to keep the medication in a dry, away from damp conditions such as bathrooms.

The intravenous solution should be kept at room temperature until it is ready for use. Once it is ready to be used, it should be mixed with the dilutant as soon as it is removed from its packaging. When the solution has been mixed and diluted appropriately, it should be given to the patient immediately. However, if immediate use is not possible, the mixture can be put into a temperature controlled fridge. It must not be frozen. Doctors can keep the mixture refrigerated for up to 24 hours. After this time, it must be disposed of.


Cyclophosphamide should be thrown away if it becomes out of date or unusable. As this is a very strong medication, care needs to be taken to dispose of it in a responsible and safe way, to ensure that it does not get into the possession of anyone not authorized to use it. Intravenous medication will be kept in a controlled medical environment, so a medical professional will be able to dispose of it in the best possible way.

For oral tablets, patients should never throw their tablets out into the regular trash. They should instead read the advice that is given by the FDA on its website about how to correctly throw away unwanted or unused medication. You should take the tablets out of their box and mix them with an inedible substance such as dirt, or cat litter. Then you need to put the mixture into a plastic sandwich bag that can be sealed shut and throw it into the trash can for collection.

The best way to get rid of drugs is via a take back scheme. These are available throughout the country and trained professionals can pick up your drugs at no cost, disposing of them safely. You can find out whether there is a take back scheme in your area by visiting the FDA's website.


Cyclophosphamide is a form of chemotherapy and therefore is a very strong and potent treatment for various form of cancers. The drug can cause some severe side effects in many patients, due to the fact that it kills white blood cells in the body. The patient can also therefore be vulnerable to various infections, which can be dangerous as the immune system can become unable to fight them. Patients should always be closely monitored throughout treatment and should stay away from conditions where infections may be rife.

The drug has been found to be very effective at reducing the multiplication of cells and has been found to increase life expectancy in patients with various forms of cancer. Compared with some other aggressive cancer treatments, Cyclophosphamide has been found to be fairly safe through many medical studies. However, there have been mixed results in some studies, finding a link between the drug and various serious side effects and conditions. Despite this, doctors remain confident in the abilities of Cyclophosphamide in treating and controlling cancer in a variety of patients. It is also a fairly flexible drug; it does not have many major interactions with other drugs, compared with some of its counterparts, and it can also be used in partnership with a number of other chemotherapy drugs.

Cyclophosphamide also has the added advantage of having two administration options. Most other chemotherapy drugs can only be administered via the intravenous route. However, Cyclophosphamide comes in tablet form, making it easier to consume and leading to lesser side effects. This can also offer patients greater flexibility throughout their treatment, being able to take the tablets home with them, rather than having to regularly come back to the hospital for injection appointments.

In all, Cyclophosphamide is a preferred and flexible treatment for a wide range of cancers, and is effective for use in both children and adults.