Cyclophosphamide: Uses, Precautions, Dosage, Interactions and Side Effects

It is a drug that belongs to the family of alkylating agents.


Cyclophosphamide is used to treat several types of cancer. It is a chemotherapy drug that works by slowing or stopping cell growth.

Cyclophosphamide also works by lowering the immune system’s response to various diseases.

It is also used to treat a specific type of kidney disease in children after other treatments have not worked.

What conditions does it treat?

  • Breast cancer
  • Neuroblastoma.
  • Acute monocytic leukemia.
  • Ovarian cancer.
  • linfoma de Burkitt.
  • Cutaneous T-cell lymphoma.
  • AML.
  • Progressive chronic lymphocytic leukemia.
  • Minimal change glomerulonephritis.
  • Hodgkin lymphoma.
  • Acute lymphocytic leukemia.
  • Multiple myeloma.
  • Follicular lymphoma.
  • Diffuse large B-cell lymphoma.
  • Retinoblastoma.
  • Mycosis fungoides.
  • Chronic lymphoid leukemia.
  • Conditioning before allogeneic hematopoietic stem cell transplantation.
  • Scleroderma lung disease.
  • Tumor de Wilms.
  • Refractory osteosarcoma.
  • Multiple sclerosis.
  • Soft tissue tumor that is usually malignant.
  • Systemic lupus erythematosus.
  • Ovarian germ cell cancer.
  • Small cell lung cancer.
  • Inflammation of the skin and muscles throughout the body.
  • Sarcoma de Ewing.
  • Granulomatosis de Wegener.


Before taking cyclophosphamide, the patient needs to tell their doctor if they are allergic to this or other chemotherapy drugs such as:

  • Busulfan.
  • Chlorambucil.

You should also report any other allergies as cyclophosphamide may contain inactive ingredients that increase the severity of the allergy.

This medication should not be used if the patient has certain medical conditions, especially if they have:


  • A decrease in bone marrow function.
  • Liver disease.
  • Renal disease.
  • Some surgery to remove the adrenal glands.

Contact with people who have chickenpox, measles, the flu, or any contagious disease should be avoided.

This is because the drug exposes the body, and the patient can contract diseases more easily or increase the impact of viruses.

Therefore, it is recommended that the patient wash their hands well to avoid infection.

You should especially avoid:

  • Contact people who have recently received vaccinations.
  • Cut, hurt, or injure yourself.
  • Exposing yourself to surgery without first consulting with your doctor about the products used during surgery.

Caution is advised when using cyclophosphamide in children because they are more sensitive to its effects, especially if they are at risk of possible infertility later in life.

Women who are pregnant or want to become pregnant should not take this medicine or breathe the powder from the tablets or capsules.

This is because this medicine can be absorbed through the skin and lungs and cause harm to an unborn baby.

In addition, this drug passes into breast milk and can harm the infant, so its consumption is not recommended when the patient is breastfeeding.

It is recommended that women of childbearing potential use reliable contraception during treatment and up to 1 year after stopping treatment.

Men should use reliable contraception during sexual activity with a female partner of childbearing age.

This precaution should be maintained during the treatment period and for up to 4 months after stopping treatment.

The patient should inform the doctor immediately if she becomes pregnant or, if not, if her partner becomes pregnant or if she thinks she might be pregnant.

Administration in specific patients


As mentioned above, its consumption is not recommended in pregnant women since severe damage has been evidenced in the baby, such as:

  • Skeletal malformations.
  • Malformations in the limbs.
  • Malformations in the eyes.
  • Psychological deviations.

Sick people

Absolute contraindications have been observed when cyclophosphamide is administered when the patient is ill.

Mainly there is a risk of developing severe adverse effects.

Adults over 60 years old

In this population, precautionary handling or monitoring is recommended, as mentioned above, since, in these patients, renal failure may increase the disposition to the development of toxicity.

Children under 12 years old

Caution and control should be maintained as there are reports of ovarian fibrosis with loss of germ cells after prolonged treatment in girls treated before puberty.

After completing treatment, girls with retained ovarian function are at increased risk of developing premature menopause.

There is also a risk of developing azoospermia and increased gonadotropin secretion despite characteristic secondary sexual development in prepubertal children.

Likewise, there is the possibility that the child under this treatment will develop testicular atrophy.


It is important to receive each scheduled dose of this medication as directed by your doctor for optimal benefits.

If the patient misses a dose, they should contact their doctor to establish a new dosing schedule. Doubling the amount to catch up is not recommended.

How to use cyclophosphamide?

This medication should be taken by mouth or administered intravenously precisely as directed by the doctor.

Dosage will depend on the medical condition the patient has, weight, response to treatment, and other treatments (such as other chemotherapy drugs and radiation) that they are receiving.

Tell the doctor about all the products the patient uses (including prescription and non-prescription drugs and herbal products).

During treatment with this medicine, you should drink more fluids than usual and frequently urinate to help avoid kidney and bladder side effects.

The patient should ask their doctor how much to drink and how often to empty their bladder each day and follow these instructions carefully.

If the patient is using the capsules, they should be swallowed whole. The tablets should not be opened, chewed, or crushed.

If there is accidental contact with broken capsules, the person should wash their hands thoroughly immediately.

It is not recommended to increase the dose or take this medicine more often without a doctor’s approval.

The condition will not improve any faster and may increase the risk of severe side effects.

Side effects

May cause:

  • Sickness.
  • Vomiting
  • Loss of appetite
  • Stomach ache.
  • Diarrhea.
  • Darkening of the skin and nails.

Nausea and vomiting can be severe. Drug therapy may be necessary to prevent or relieve nausea and vomiting in some cases.

Diet changes, such as eating several small meals or limiting activity, can help lessen some of these effects.

If these effects persist or worsen, the patient should promptly notify their doctor or pharmacist.

Temporary hair loss can occur. Hair growth should return after the treatment is over, or it may even return during treatment.

However, new hair may have a different color or texture.

People using this medicine can have serious side effects. Careful supervision by a doctor can lower your risk.

Tell a doctor right away if you experience any of these unlikely but serious side effects:

  • Signs of kidney or bladder problems (such as a change in the amount of urine, bloody urine).
  • Sores in the mouth
  • Joint pain
  • Easy bruising.
  • Bleeding from menstrual periods.
  • Existing wounds that are slow to heal.
  • Bloody stools.
  • Severe stomach or severe abdominal pain.
  • Yellowish eyes or skin
  • Dark urine
  • Mental or mood changes.
  • Muscle weakness or spasm

In rare cases, this drug can cause severe effects on the heart, mainly when used in high doses or combined with radiation therapy or other chemotherapy drugs.

Urgent medical attention should be sought if the patient has:

  • Pain in the chest, jaw, or left arm.
  • Difficulty breathing.
  • Irregular heartbeat
  • Symptoms of heart failure (such as shortness of breath, swelling of the ankles or feet, unusual tiredness, unusual and sudden weight gain).

This medicine can decrease the body’s ability to fight infection.

The patient should notify their physician immediately if they develop any signs of infection, such as fever, chills, or a persistent sore throat.

Cyclophosphamide can lower the chance of having children in both men and women.

Sterility is usually temporary with this drug, but it can be permanent in some cases. A doctor should be consulted for more details.

Although cyclophosphamide is used to treat cancer, in some patients, it may increase the risk of developing another form of cancer, sometimes months or years after treatment.

The doctor needs to monitor the patient during treatment closely. You should also see your doctor regularly after finishing treatment.

It is necessary to inform the doctor immediately if the patient presents:

  • Unusual growths or bumps.
  • Inflamed glands.
  • Sudden or unexplained weight loss.
  • Night sweats.
  • Pain in the pelvis
  • Painful or frequent urination

A severe allergic reaction to this drug is unlikely, but seek immediate medical attention if it occurs.

Symptoms of a severe allergic reaction can include:

  • Rash.
  • Itch.
  • Swelling (especially of the face, tongue, and throat).
  • Severe dizziness
  • Difficulty breathing.


Some products that may interact with this drug include:

  • Allopurinol.
  • Chloramphenicol.
  • Chloroquine
  • Digoxin .
  • Nalidixic acid.
  • Phenobarbital.
  • Phenothiazines
  • Primidone.
  • Grass of San Juan.
  • Turmeric (curcumin).

It is essential to mention that this medication may increase the risk of severe side effects if it interacts with other medicines.

Therefore, the patient must inform his doctor about other treatments that he may be performing.


Symptoms of overdose with this medicine are fainting or shortness of breath. The patient should immediately seek medical attention if this happens.

On the other hand, it is recommended to ingest only the dose indicated by the doctor since otherwise, significant complications may arise.