Dacarbazine is a chemotherapy drug that is given as a treatment for some types of cancer. It is most commonly used to treat melanoma, Hodgkin lymphoma and soft tissue sarcomas. This information describes dacarbazine, how it is given and some of its possible side effects. It should ideally be read with our general information about chemotherapy and about your type of cancer, which give further information and advice.

If you have any further questions you can ask your doctor or nurse at the hospital where you are having your treatment, or speak to one of our cancer support service nurses.

Dacarbazine is a pale yellow liquid.

Dacarbazine can be given:

• By slow injection into a vein (intravenously) through a fine tube inserted into the vein (cannula). It may also be given through a central line which is inserted under the skin into a vein near the collarbone, or into a PICC line inserted into a vein in the crook of your arm.
• By drip (infusion) through the cannula or line. The infusion takes about 15 to 30 minutes.

Chemotherapy is usually given as a course of several sessions (or cycles) of treatment over a few months. The length of your treatment and the number of cycles you have will depend on the type of cancer for which you are being treated. Your nurse or doctor will discuss your treatment plan with you.

Each person's reaction to chemotherapy is different. Some people have very few side effects, while others may experience more. The side effects described in this information will not affect everyone who is given dacarbazine, and may be different if you are having more than one chemotherapy drug.

We have outlined the most common side effects and some of the less common ones, so that you can be aware of them if they occur. However, we have not included those that are very rare and therefore extremely unlikely to affect you. If you do notice any effects which you think may be due to the drug, but which are not listed in this information, please discuss them with your doctor or chemotherapy nurse.

Feeling sick (nausea) and being sick (vomiting) If you do feel sick this may begin 2–3 hours after the treatment is given and last for a few days. Your doctor can prescribe very effective anti-sickness (anti-emetic) drugs to prevent, or greatly reduce, nausea and vomiting. If the sickness is not controlled, or continues, tell your doctor; they can prescribe other anti-sickness drugs which may be more effective. Some anti-sickness drugs can cause constipation. Let your doctor or nurse know if this is a problem.

Lowered resistance to infection Dacarbazine can reduce the production of white blood cells by the bone marrow, making you more prone to infection. This effect can begin seven days after treatment has been given, and your resistance to infection usually reaches its lowest point 21–25 days after chemotherapy. Your blood cells will then increase steadily, and will usually have returned to normal levels within 32–40 days.

Contact your doctor or the hospital straightaway if:

• your temperature goes above 38ºC (100.5ºF)
• you suddenly feel unwell (even with a normal temperature).

You will have a blood test before having more chemotherapy, to make sure that your cells have recovered. Occasionally it may be necessary to delay your treatment if the number of blood cells (the blood count) is still low.

Bruising or bleeding Dacarbazine can reduce the production of platelets (which help the blood to clot). Let your doctor know if you have any unexplained bruising or bleeding, such as nosebleeds, blood spots or rashes on the skin, or bleeding gums.

Anaemia (low number of red blood cells) While having treatment with dacarbazine you may become anaemic. This may make you feel tired and breathless. Let your doctor or nurse know if you develop these symptoms.

Loss of appetite A dietitian or specialist nurse at your hospital can give advice and tips on boosting appetite, coping with eating difficulties and maintaining weight.

Pain on injection While dacarbazine is being given, it can cause pain at the place where the injection is given, or along the vein. If you feel pain, tell the nurse or doctor, as they can help by slowing the drip down.

Diarrhoea This can usually be easily controlled with medicine, but tell your doctor if it is severe or if it continues. It is important to drink plenty of fluids if you have diarrhoea.

Hair loss This is rare, but your hair may thin, or occasionally fall out completely. If this happens it usually begins about 3–4 weeks after the first dose of dacarbazine, although it may occur earlier. Hair loss is temporary, and your hair will regrow once the treatment ends.

Your liver may be temporarily affected Dacarbazine may cause changes in the way that your liver works, although your liver will return to normal when the treatment is finished. This is very unlikely to cause you any harm, but your doctor will monitor this carefully. Samples of your blood will be taken from time to time to check your liver is working properly.

Sensitivity of the skin to sunlight During treatment with dacarbazine, and for several months afterwards, you will be more sensitive to the sun, and your skin may burn more easily than normal. You can still go out in the sun, but should wear a high protection factor suncream and cover up with clothing and a hat.

Allergic reaction Some people receiving dacarbazine have an allergic reaction to the drug, either on the first dose or sometimes with further doses. Signs of an allergic reaction include skin rashes and itching, a high temperature, shivering, redness of the face, a feeling of dizziness, a headache, breathlessness, anxiety and a need to pass urine.

You should quickly report any of these signs to your doctor or nurse, as medicine can be given to reduce these effects.

A flu-like effect This can occur up to a week after you have had dacarbazine, and may last for a week or more. You may have headaches, aching joints or muscles, a temperature, weakness and chills. If this does happen, it is important that you drink plenty of fluids and get plenty of rest.

Sore mouth and ulcers Your mouth may become sore, or you may notice small ulcers during this treatment. Drinking plenty of fluids, and cleaning your teeth regularly and gently with a soft toothbrush, can help to reduce the risk of this happening. Tell your doctor if you do have any of these problems, as special mouthwashes and medicines to prevent or clear any mouth infection can be prescribed.

Taste changes You may notice that your food tastes different. Normal taste will come back after the treatment finishes.

Risk of blood clots Cancer can increase your risk of developing a blood clot (thrombosis), and having chemotherapy may increase this risk further. A blood clot may cause symptoms such as pain, redness and swelling in a leg, or breathlessness and chest pain. Blood clots can be very serious so it is important to tell your doctor straightaway if you have any of these symptoms. However, most clots can usually be successfully treated with drugs to thin the blood. Your doctor or nurse can give you more information.

Other medicines Some medicines can be harmful to take when you are having chemotherapy. Tell your doctor about any medications you are taking, including non-prescribed drugs such as complementary therapies and herbal drugs.

Facial flushing Some people find that their face flushes while the drug is being given.

Fertility Your ability to become pregnant or father a child may be affected by taking this drug. It is important to discuss fertility with your doctor before starting treatment.

Contraception It is not advisable to become pregnant or father a child while taking dacarbazine, as the developing foetus may be harmed. It is important to use effective contraception while taking this drug, and for at least a few months afterwards. Again, discuss this with your doctor.

This section is based on our Dacarbazine factsheet which has been compiled using information from a number of reliable sources, including:

• Martindale: The Complete Drug Reference (35th edition). Eds. Sweetman et al. Pharmaceutical Press, 2007.
• British National Formulary (54th edition). British Medical Association and Royal Pharmaceutical Society of Great Britain, September 2007.
• The Medicines.org.uk website – www.medicines.org.uk (November 2007).
• The Chemotherapy Source Book (3rd edition). Ed. Perry. Lippincott, Williams and Wilkins, 2001.

For further references, please see general bibliography.