BMA Concise Guide to Medicine & Drugs

Cyclophosphamide

Brand name None

Used in the following combined preparations None

QUICK REFERENCE

Drug group Anticancer drug

Overdose danger rating Medium

Dependence rating Low

Prescription needed Yes

Available as generic Yes

GENERAL INFORMATION

Cyclophosphamide belongs to a group of anticancer drugs known as alkylating agents. It is used for a wide range of cancers, including lymphomas (lymph gland cancers), leukaemias, and solid tumours. It is commonly given together with radiotherapy or other drugs. Cyclophosphamide has also been used for autoimmune diseases, such as rheumatoid arthritis and systemic lupus erythematosus when it involves the kidneys.

Cyclophosphamide causes nausea, vomiting, and hair loss, and can affect the heart, lungs, and liver. It can also cause bladder damage in susceptible people because it produces a toxic substance called acrolein. To reduce toxicity, people considered to be at risk may be given a drug called mesna before and after each dose of cyclophosphamide. Also, because the drug often reduces production of blood cells, it may lead to abnormal bleeding and increased risk of infection. It may also reduce fertility in men and women.

INFORMATION FOR USERS

How taken/used Tablets, injection.

Frequency and timing of doses Varies from once daily to every 3 weeks, depending on the condition being treated.

Dosage range Dosage is determined individually according to the nature of the condition, body weight, and response.

Onset of effect Some effects may appear within hours of starting treatment. Full beneficial effects may not be felt for many weeks.

Duration of action Several weeks.

Diet advice High fluid intake with frequent bladder emptying is recommended. This will usually prevent the drug causing bladder irritation.

Storage Keep in original container at room temperature out of the reach of children. Protect from light.

Missed dose Injections are given only in hospital. If you are taking tablets, take the missed dose as soon as you remember. If your next dose is due within 6 hours, take a single dose now and skip the next. Tell your doctor that you missed a dose.

Stopping the drug The drug will be stopped under medical supervision (injection). Do not stop taking the drug without consulting your doctor (tablets); stopping the drug may lead to worsening of the underlying condition.

Exceeding the dose An occasional unintentional extra dose is unlikely to cause problems. Large overdoses may cause nausea, vomiting, and bladder damage. Notify your doctor.

POSSIBLE ADVERSE EFFECTS

Cyclophosphamide often causes nausea and vomiting, which usually diminish as your body adjusts to the drug. Hair loss is also common, and women often experience irregular periods. More rarely, breathlessness and mouth ulcers may occur; if so, you should discuss with your doctor. Blood in the urine may be a sign of bladder damage and requires prompt medical attention. Those thought to be at risk of bladder damage may be given mesna before and after doses of cyclophosphamide.

INTERACTIONS

General note A number of drugs reduce the effects of cyclophosphamide and increase the risk of side effects. Such drugs include allopurinol, chloramphenicol, chloroquine, imipramine and phenothiazines (e.g. chlorpromazine).

SPECIAL PRECAUTIONS

Cyclophosphamide is prescribed only under close medical supervision, taking account of your present condition and medical history. However, be sure to tell your doctor if:

· You have liver or kidney problems.

· You have porphyria.

Pregnancy Not usually prescribed. Cyclophosphamide may cause birth defects. Pregnancy should be avoided during, and for 3 months after, treatment. Discuss with your doctor.

Breast-feeding Not advised. The drug passes into the breast milk and may affect the baby adversely. Discuss with your doctor.

Infants and children Reduced dose necessary.

Over 60 No special problems.

Driving and hazardous work No known problems.

Alcohol No problems expected, but avoid excessive amounts.

PROLONGED USE

Prolonged use of this drug may reduce the production of blood cells in the bone marrow. It may also cause pigmentation of the nails, palms, and soles of the feet.

Monitoring Periodic checks on blood composition and blood chemistry are usually required.