Cytosine arabinoside
Cytosine arabinoside belongs to a group of drugs known as antimetabolites. It resembles
a normal cell nutrient needed by cancer cells to grow. The cancer cells take up Cytosine
arabinoside, which then interferes with their growth.
Cytosine arabinoside is used to treat:
- certain types of leukemias
- non-Hodgkin's lymphoma
Side effects of Cytosine arabinoside
Temporary reduction in the production of blood cells by the bone marrow.
This can result in anaemia, risk of bruising or bleeding and infection. This effect can
begin about seven days after the treatment has been given and the number of blood cells
usually reaches its lowest point at 10-14 days after the chemotherapy. The number of blood
cells will then increase steadily and will usually return to normal within 21-28 days.
The extent to which your blood cells are reduced depends on the dose of chemotherapy
you receive and which other chemotherapy drugs, if any, are given in combination. Your
doctor can advise you how likely it is that your blood cells will be lowered by the
chemotherapy. Your blood will be checked regularly to see how well your bone marrow is
working.
If your temperature goes above 38°C (100.5°F), or you develop any unexplained
bruising or bleeding, or you suddenly feel unwell, even with a normal temperature, contact
your doctor or the hospital straight away.
Nausea (feeling sick) and vomiting. There are now very effective
anti-sickness drugs to prevent or greatly reduce nausea and vomiting. If it does happen it
may begin after the treatment is given and last up to several hours. If the sickness is
not controlled, or continues, tell your doctor. They can prescribe other anti-sickness
drugs which may be more effective.
Diarrhoea. This can usually be easily controlled with medicine but
tell your doctor if it is severe or continues. It is important to drink plenty of fluids
if you do have diarrhoea.
Loss of appetite. A dietician or specialist nurse at your hospital can
give advice.
Raised levels of uric acid in the blood. A drug called allopurinol may
be given to stop this happening. It may also help to drink plenty of fluids. While you are
taking Cytosine arabinoside your uric acid levels will be checked regularly by blood
tests.
Gritty eyes due to inflammation of the lining of the eyelids
(conjunctiva). If this happens it is important to tell your doctor. They can prescribe
soothing eye drops.
Sore mouth and taste change. 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 reduce the risk of this
happening. Tell your doctor if you do have any of these problems as they can prescribe
special mouthwashes and medicine to prevent or clear any mouth infection.
You may notice that your food tastes different. Normal taste will come back after the
treatment finishes.
Less common side effects of Cytosine arabinoside
Hair loss. Hair loss is uncommon but hair may thin, or occasionally be
lost completely. If this happens it usually begins about 3-4 weeks after starting
treatment, although it may occur earlier. It is temporary, and the hair will regrow once
the treatment is finished.
Your liver may be temporarily affected. Cytosine arabinoside may cause
changes in the way that your liver works, which 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
function.
Lack of energy (lethargy), sleepiness, confusion and loss of balance.
This is very rare and only happens with high dose treatment. If you notice any of these
effects it is important to tell your doctor.
Changes to the lungs. Cytosine arabinoside may cause some changes to
lung tissue. Tell your doctor if you notice any cough or breathlessness.
Soreness and redness of the palms of the hands and soles of the feet
(sometimes known as palmar plantar or hand-foot syndrome). This is temporary and will
improve when the treatment is finished.
Skin changes. Cytosine arabinoside can cause a rash, which may be
itchy. Your doctor can prescribe medicine to help with this.
A flu-like effect can occur after the drug is given, and may last for
a few days. You may have headaches, aching joints or muscles, a temperature, lethargy (a
feeling of having no energy) and chills. If this does happen, it is important that you
drink plenty of fluids and get plenty of rest.
Effect on the nervous system. At very high doses Cytosine arabinoside
can cause some damage to the nerves inside and outside the brain. This may cause a variety
of symptoms, including fits (seizures) and mood changes. |