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Cyclophosphamide (Injection)

Q: What Precautions Should I Take When Taking Or Using This Medication?

Inform your healthcare professional if: You are allergic to this medication or any of the other ingredients of this medication. You are taking any other medications, including supplements, traditional medications and herbal remedies. You have any other medical conditions such as heart, lung, liver or kidney conditions. You are going to receive any vaccination or surgery, including dental surgery. You have any plans to start a family in the future. Cyclophosphamide may have an anti-fertility effect, which could be irreversible. You should discuss fertility preservation options with your doctor before starting treatment. You should not become pregnant during treatment. You should use an effective birth control method during treatment and at least 1 year after stopping Cyclophosphamide. If you have a partner who could become pregnant, you should use an effective birth control method during treatment and for at least 6 months after stopping Cyclophosphamide. You should not breastfeed during treatment with Cyclophosphamide and at least 6 weeks after stopping Cyclophosphamide.

Cyclophosphamide is used to treat leukaemias (blood cancers), lymphomas (cancers that affects the lymphatic system) and solid tumours (such as ovarian cancer, breast cancer, testicular cancer, small cell lung cancer, neuroblastoma and Ewing’s sarcoma). Learn how to use the medication, its common side effects, special precautions to watch out for, and more.

Article last reviewed 16 December 2025
13 mins read

What is this medication for?

Cyclophosphamide is used to treat leukaemias (blood cancers), lymphomas (cancers that affects the lymphatic system) and solid tumours (such as ovarian cancer, breast cancer, testicular cancer, small cell lung cancer, neuroblastoma and Ewing’s sarcoma). It may be used in combination with other types of chemotherapy agents.

Cyclophosphamide works by damaging the DNA inside cells, and this stops cancer cells from multiplying and growing.

How should I take or use this medication?

Cyclophosphamide is injected into the vein. The infusion duration ranges from 10 minutes to a few hours, and it may also be given as a continuous infusion, depending on the treatment protocol.

What precautions should I take when taking or using this medication?

Inform your healthcare professional if:
- You are allergic to this medication or any of the other ingredients of this medication.
- You are taking any other medications, including supplements, traditional medications and herbal remedies.
- You have any other medical conditions such as heart, lung, liver or kidney conditions.
- You are going to receive any vaccination or surgery, including dental surgery.
- You have any plans to start a family in the future.
  - Cyclophosphamide may have an anti-fertility effect, which could be irreversible. You should discuss fertility preservation options with your doctor before starting treatment.
You should not become pregnant during treatment. You should use an effective birth control method during treatment and at least 1 year after stopping Cyclophosphamide.
If you have a partner who could become pregnant, you should use an effective birth control method during treatment and for at least 6 months after stopping Cyclophosphamide.
You should not breastfeed during treatment with Cyclophosphamide and at least 6 weeks after stopping Cyclophosphamide.

What are some common side effects of this medication?

The table below will list some of the common side effects as well as the rare but serious side effects.

Side Effect	Management
Nausea or vomiting	Take small and frequent meals. Avoid foods and smells that may make you feel nauseous, such as oily, fried or strong-smelling food. Avoid tight-fitting clothes around the waist. Your doctor may prescribe medications to help relieve or prevent nausea or vomiting. Take these as instructed.
Poor Appetite	This may be worsened by a change in taste of food and/or nausea. Try different flavours of food and small frequent meals. For poor appetite, try to include nutritional supplements (such as milk supplements) into your diet.
Mouth ulcers or sores. This can occur on the tongue, the sides of the mouth or in the throat and can lead to an infection.	Rinse your mouth regularly with an alcohol-free mouthwash or salt water to help reduce the chances of an infection. Brush your teeth gently after eating and at bedtime with a soft bristle toothbrush. If you have dentures, rinse and brush your dentures after eating and soak them in denture solution overnight. Avoid spicy food and take soft foods e.g. porridge. Your doctor may prescribe medications to help relieve or prevent the mouth sores. Use these as instructed. Inform your doctor if you are eating or drinking a lot lesser because of mouth pain.
Diarrhoea (loose and frequent stools)	Drink plenty of clear fluids (at least 2 litres or 8 cups every day). Eat food that is gentler on the stomach such as porridge or soup. Avoid milk, dairy products, high-fibre food and oily or spicy food. Your doctor may prescribe medications to help relieve diarrhoea. Take these as instructed. Proceed to the A&E Department immediately if you have very bad diarrhoea (for example, an increase in bowel movement of more than 4 times per day) that does not improve even after taking anti-diarrhoeal medications.
Hair loss This is a temporary side effect and may be more obvious by the second week of treatment. You may lose all the hair on your head and may even lose your eyebrows, eyelashes or body hair.	Consider cutting your hair short before chemotherapy, using wigs or using head coverings like hats or scarves. Use a mild shampoo (such as baby shampoo) to wash your hair and scalp. Your hair will grow back a few weeks after chemotherapy is completed.
Nail changes that may affect both fingernails and toenails. Your nails may Become more brittle and break easily Turn darker in colour Develop ridges (lines) on the surface, which may give an uneven appearance Rarely, nails may come off.	Try to keep your nails short, clean and dry. Avoid contact with harsh chemicals e.g. detergent or dish-washing liquids. Wearing gloves when washing dishes or using detergents can help protect your nails during treatment. If you experience pain, redness or swelling around your nails, inform your doctor.
Decrease in white blood cell count. This may increase your chances of getting an infection.	To reduce the risk of infection: Maintain good hand hygiene. Wash your hands before handling food and after using the toilet. Avoid crowds and do not go near people who are sick. Wear a mask if necessary. Eat freshly cooked and well-cooked food. Avoid raw meats, vegetables and eggs, or half-cooked or uncooked food. Proceed to the A&E department immediately if you have any signs of infection such as A fever of 38°C and above Chills Bad sore throat Pain when you pass urine Mouth sores or wounds that do not heal Avoid taking Paracetamol to relieve fever as this may mask your fever and delay treatment of the infection.
Decrease in platelet count. Low platelet levels can increase your chance of bleeding.	To reduce the risk of bleeding: Be careful when using sharp objects such as scissors or knives. Brush your teeth gently with a soft bristle toothbrush to prevent gum bleeding. Try not to bruise, cut or knock yourself. Apply direct pressure to any cuts or wounds to help stop bleeding. Proceed to the A&E department immediately if you have: Bruising without a cause or bruises that get larger in size Black, sticky stools Blood in the urine Coughing out blood or vomit that looks like coffee grounds Bleeding which does not stop
Decrease in the number of red blood cells (anaemia) As your red blood cells help to carry oxygen to the different parts of your body, this may cause you to feel tired more easily.	Proceed to the A&E department immediately if you have: Unusual giddiness or light-headedness that does not go away Severe breathlessness or rapid breathing An unusually fast heartbeat while resting
Bladder irritation. This may lead to discomfort when passing urine or blood in the urine.	Drink at least 2 to 3 litres of fluids every day unless informed by your doctor to drink less fluids.
Liver problems may rarely occur if you are taking or receiving other medications that may also harm the liver.	Proceed to the A&E department immediately if you experience any: Weight gain Severe abdominal pain Dark or tea-coloured urine Pale or light-coloured stools Yellowing of skin or eyes Nausea and vomiting with a loss of appetite
Symptoms of drug allergy including one or more of the following: Swollen face/eyes/lips/tongue Difficulty in breathing Itchy skin rashes over your whole body	If you experience any of these symptoms, you should stop your medication and see your healthcare professional immediately.
Risk of blood disorders/leukaemia and secondary cancers.	This occurs very rarely. Please discuss with your doctor if you have concerns.

What food or medication should I avoid when I take or use this medication?

Avoid eating any raw, uncooked or under-cooked food as your immunity is weakened.

What else should I know about this medication?

Tips to help manage your condition while you are on Cyclophosphamide

Exercise

Light exercise is recommended as it helps to improve mobility, balance, and even emotional well-being. Avoid strenuous exercise, and rest when you are feeling tired.

Medical and dental treatment

If you need to go to the hospital for any reason other than cancer, always inform the doctors and nurses that you are receiving anti-cancer treatment.

Talk to your cancer doctor if you think you need dental treatment.

Always inform your dentist that you are receiving anti-cancer treatment.

Seek support if you feel overwhelmed

It is normal to feel fearful or worried about your condition.

Do not be afraid to share your concerns with your healthcare team or loved ones.

There may be resources and support available to help you.

Disclaimer

Please take note that the above is not a complete list of all possible side-effects. If you have any concerns about your medication or if you have other side-effects that you think are caused by this medication, please consult your doctor or pharmacist. If you take more than the recommended dose, please seek medical advice immediately. The information provided on this page does not replace information from your healthcare professional. Please consult your healthcare professional for more information.

This article is jointly developed by members of the National Medication Information workgroup. The workgroup consists of cluster partners (NHG Health, National University Health System and SingHealth), community pharmacies (Guardian, Unity and Watsons) and Pharmaceutical Society of Singapore. The content does not reflect drug availability and supply information in pharmacies and healthcare institutions. You are advised to check with the respective institutions for such information.