Cyclophosphamide (Cytoxan) is a chemotherapy drug that is mainly used in the treatment of the following types of cancers.
- Breast cancer
- Non-Hodgkin’s disease
- Chronic lymphocytic leukemia
- Ovarian cancer
- Bladder cancer
- Bone and soft tissue sarcoma
- Wilm's tumor
Cyclophosphamide is a white colored powder which makes a colorless solution when dissolved. This solution is usually administered through the vein. It is also available as a white colored 25 mg or 50 mg tablet. A central line (small catheter into a big vein) or a portocath (similar device which is placed under the skin) is commonly used to administer cyclophosphamide to the vein.
Side effects associated with cyclophosphamide may vary from person to person. Some patients may experience significant side effects while others may experience very minimal side effects. It is not possible to predict who is going to have more severe side effects. All the side effects described here will not affect everyone. Most patients will have the common side effects like hair loss, while some other side effects may affect few patients, and may not trouble some others. In this section we will discuss the most common side effects and many less common side effects of cyclophosphamide
Common side effects
Bone marrow suppression and lowering of blood counts
Use of cyclophosphamide like many other chemotherapy drugs can cause suppression of the bone marrow and this can result in decreased production of all types of blood cells made from bone marrow. When the white cell production is affected, the condition is called neutropenia. Since white cells are the main types of cells that fight infection, lowering of white cell count can affect your ability to fight infections. It is important to realize that if you get an infection while your white cell count is low (called neutropenia) you may be at significant risk of having serious problems with the infection. Because of this reason if you ever develop a fever while you are on any type of chemotherapy, it is important to make sure that your white blood count is not low. If on the other hand if your white cell count is low with fever (a condition called febrile neutropenia consisting of fever and low white cell count), many times you will have to be admitted to the hospital for intravenous antibiotic treatment. Lowering of red blood cells can result in a condition called anemia. Since red cells are the major carriers of oxygen from lung to different parts of the body, a decrease in red cells (or red colored material in the red cells called hemoglobin) you may experience fatigue, lack of energy and tiredness. If another type of blood component called platelets go down, you may be at risk of bleeding or bruising, since platelets have a major role in prevention of bleeding. The blood counts may start falling in about a week’s time after treatment, however the lowest points in the blood counts are usually seen around 10 to 14 days after treatment. Usually from this point onwards the blood counts usually recover and reaches normal values within 21-28 days.
The degree of lowering of the blood counts will depend on the type and dose of chemotherapy. Usually your doctor will check the blood counts weekly to monitor your blood counts, however if the blood counts are lower, your doctor may ask you to have blood counts done more often. If the red cells or platelets are very low your doctor may suggest you to have blood or platelet transfusions.
If any time during your course of chemotherapy you experience fever with temperature going above 38C (100.5F), or you develop any unexplained bruising or bleeding, or you suddenly feel unwell, even with a normal temperature, contact your doctor or the hospital emergency room immediately.
Hair loss is relatively severe with cyclophosphamide. This usually starts 3-4 weeks after the first dose of cyclophosphamide, and may gradually worsen with subsequent doses of cyclophosphamide.
Nausea and vomiting
Nausea is the sick feeling that you get when you are going to have vomiting. Cyclophosphamide treatment may cause nausea and vomiting in some patients, however there are very effective medications available, which can be used to prevent or greatly reduce nausea and vomiting. Commonly the nausea and vomiting may occur few hours after the administration of chemotherapy and may last one or more days. Your doctor will give you prescription for nausea medications, and with prudent use of these nauseas medications only few patients will have significant nausea or vomiting. If the nausea or vomiting gets severe your doctor may admit you to the hospital to give you intravenous fluids and anti-nausea medications.
Bladder toxicity may present as pain during urination and or increased frequency of urination. This complication can begin within 24 hours of treatment with cyclophosphamide or may be delayed by several weeks. This may be reversed by stopping further drug administration.
Skin and nail color changes
Treatment with cyclophosphamide may result in darkening of your skin. This is due to excess production of pigments. Your skin color may return to normal a few months after the treatment has completed
Stopping of menstrual periods
You may experience stopping of menstrual flow with cyclophosphamide. This is due to ovarian failure and may be permanent resulting in infertility.
Loss of appetite
Cyclophosphamide treatment may result in loss of appetite.
Less common side effects
Mouth ulcers and taste change
You may develop soreness in the mouth, or may notice small ulcers in the inner parts of your cheeks, back of throat or tongue. Drinking plenty of fluids and having good mouth care with gentle brush may decrease the chance of developing mouth sours. If this happens, your physician will give you some lotions to apply to the affected areas. You may also have change or loss of taste for food while undergoing chemotherapy. The food may taste different. This problem usually disappears when the treatment is completed and normal taste will come back
This is condition in which body retains excess amounts of water with the production of concentrated urine. This may result in decrease in serum sodium, subsequently causing various complications.
Cardiac toxicity may be seen with high dose chemotherapy using cyclophosphamide.
Increased risk of other cancer
Treatment with cyclophosphamide may result in increased risk of other caners including leukemia and bladder cancer.
Suppression of immune system
Cyclophosphamide may suppress the immune system making you more susceptible to infection and this occurs independent of the white cell count.
Cyclophosphamide treatment may result in allergic reactions like running nose, irritation of the nose and throat. These usually disappear within 2-3 days.
Cyclophosphamide treatment may result in lung toxicity. Even though this is rare, you must alert your physician to this possibility if you develop any unexpected shortness of breath.
Liver function abnormalities
Cyclophosphamide may interfere with the normal working of liver causing abnormal liver function tests.
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