PURI-NETHOL™

Mercaptopurine tablets 50mg

What is in this leaflet

Please read this leaflet carefully before you start taking PURI-NETHOL
tablets.

This leaflet answers some common questions about PURI-NETHOL tablets. It does
not contain all the available information.

It does not take the place of talking to your doctor or pharmacist.

All medicines have risks and benefits. Your doctor has weighed the expected
benefits of you taking PURI-NETHOL against the risks this medicine could have
for you.

If you have any concerns about taking this medicine, ask your doctor or
pharmacist.

Keep this leaflet with your medicine. You may need to read it again.

What PURI-NETHOL is used for

PURI-NETHOL contains the active ingredient mercaptopurine.

PURI-NETHOL is used to treat acute myelogenous leukaemia and acute
lymphoblastic leukaemia. It can also be used to treat chronic granulocytic
leukaemia. These are different types of cancer affecting the blood. In people
with blood cancer, abnormal blood cells are formed in the bone marrow which
multiply uncontrollably, crowding out and interfering with the vital functions
of normal healthy blood cells.

Your doctor may have prescribed PURI-NETHOL for another purpose.

PURI-NETHOL belongs to a group of medicines called anti-neoplastic agents.
Within this group, PURI-NETHOL belongs to a class of medicines called purine
antimetabolites. These medicines are used to treat blood cancers.

PURI-NETHOL is often given in combination with other medicines used to treat
cancer of the blood.

PURI-NETHOL works by interfering with the function of the bone marrow and
reducing the number of abnormal blood cells which are causing your illness.

Ask your doctor if you have any questions about why PURI-NETHOL has been
prescribed for you.

PURI-NETHOL is available only with a doctor's prescription.

Use in children and elderly people

PURI-NETHOL is used in children, at doses similar to those used in adults.

PURI-NETHOL can also be used in elderly people at the same doses as used in
younger adults, unless they have kidney or liver disease.

Before you take PURI-NETHOL

When you must not take it

Do not take it if:

• You have ever had an allergic reaction before to mercaptopurine or to any
  of the ingredients in PURI-NETHOL listed at the end of this leaflet.
• The packaging is torn or shows signs of interference, or if the tablets
  appear to be broken, damaged or discoloured.
• The expiry date on the packaging has passed. If you take this medicine
  after the expiry date has passed, it may not work as well. If the pharmacist
  has repacked the medicine for you, there may not be an expiry date on the
  pack.

Before you start taking PURI-NETHOL

Tell your doctor if:

• You have taken PURI-NETHOL or a medicine called Lanvis™ (thioguanine)
  before and it didn't work.
• You have been, or plan to be vaccinated with a live vaccine.
• You are pregnant or plan to become pregnant.
  
  PURI-NETHOL may be harmful to an unborn baby when taken by a pregnant woman or
  by the unborn baby's father. It is recommended that you avoid becoming
  pregnant while taking PURI-NETHOL.
  
  If you are already pregnant, your doctor will weigh up the expected benefits
  of PURI-NETHOL to you against the possible risks to your unborn baby.
• You are breastfeeding or planning to breastfeed.
  
  The active ingredient in PURI-NETHOL, mercaptopurine, passes into breast milk,
  so mothers taking PURI-NETHOL should not breastfeed.

• You have any other health problems, especially:
  • Liver disease
  • Kidney disease
  • Thiopurine methyltransferase deficiency (a rare enzyme disorder)
• You are allergic to any other medicines, foods, dyes or preservatives.

If you have not told your doctor about any of the above, please do so before
taking PURI-NETHOL.

Taking other medicines

Some medicines may affect the way others work.

Tell your doctor if you are taking any other medicines, including the oral
contraceptive pill or medicines you buy without a prescription from a pharmacy,
supermarket or health food shop.

If you are taking any of the following medicines, please tell your doctor
before taking PURI-NETHOL:

• Allopurinol (Zyloprim™, Z300™, Allorin™, Apo-Allopurinol™, Progout™), used
  to treat gout.
• Anti-inflammatory medicines used to treat ulcerative colitis and Crohn's
  disease, such as olsalazine (Dipentum™), mesalazine (Asacol™, Pentasa™) and
  sulphasalazine (Colizine™, Salazopyrin™).
• Anticoagulant medicines used to thin the blood, such as warfarin
  (Coumadin™, Marevan™).
• Thioguanine (Lanvis™) also used to treat blood cancers.

Your doctor will be able to tell you more about what to do when taking
PURI-NETHOL with other medicines.

PURI-NETHOL is often used in combination with other medicines used to treat
cancer.

Taking PURI-NETHOL

How much to take

Take PURI-NETHOL exactly as your doctor has prescribed.

Your doctor will tell you how many PURI-NETHOL tablets to take each day.

Your doctor will calculate the dose based on either your body weight or your
body surface area (the area of skin you have). If you have liver or kidney
problems, your doctor may decide to reduce your PURI-NETHOL dose.

In adults and children the usual dose is 2.5mg per kilogram of body weight
per day, or 50mg to 75mg per square metre of body surface area daily.

Your doctor will calculate your PURI-NETHOL dose for you. Your doctor may
adjust the dose depending to the type of blood cancer you have, your response to
treatment and other medicines being used to treat your illness.

Never take more tablets than your doctor has prescribed.

Your doctor may do regular blood and urine tests to make sure that
PURI-NETHOL is working for you.

How to take it

Swallow tablets whole with a glass of water.

If you need to take half a tablet, you should protect your hands. Do not
breathe in any powder from halved tablets.

If you forget to take it

Do not take an extra dose. Wait until the next dose and take your normal dose
then.

Do not try to make up for the dose that you missed by taking more than one
dose at a time.

If you are not sure what to do, ask your doctor or pharmacist.

If you take too much (overdose)

Immediately telephone your doctor or the National Poisons Information Centre
(0800 POISON or 0800 764 766) for advice, or go to Accident and Emergency at
your nearest hospital, if you think that you or anyone else has taken too much
PURI-NETHOL. Do this even if there are no signs of discomfort or poisoning.

You may need urgent medical attention.

Keep phone numbers for these places handy.

An overdose of PURI-NETHOL can cause nausea, vomiting, diarrhoea and loss of
appetite. It could have serious effects on your bone marrow, blood cells and the
way your liver functions.

If you are not sure what to do, contact your doctor or pharmacist.

While you are taking PURI-NETHOL

Things you must do

Tell all doctors, dentists and pharmacists treating you that you are taking
PURI-NETHOL.

Tell your doctor if you become pregnant while taking PURI-NETHOL.

As with many medicines used to treat cancer, you should use reliable
contraception when taking PURI-NETHOL, whether you are male or female.

Tell your doctor if, for any reason, you have not taken PURI-NETHOL exactly
as prescribed. Otherwise, your doctor may think it is not working for you and
change your medicine unnecessarily.

Tell your doctor if you feel that PURI-NETHOL is not helping your condition.

Things you must not do

Do not stop taking PURI-NETHOL or change the dose without first checking with
your doctor.

Do not let yourself run out of medicine over the weekend or on holidays.

Do not give PURI-NETHOL to anyone else even if they have the same condition
as you.

Do not take any other medicines whether they require a prescription or not
without first asking your doctor or a pharmacist.

Do not drive a vehicle or operate machinery until you know how PURI-NETHOL
affects you.

Side-Effects

All medicines can have unwanted side effects. Sometimes they may be serious,
but often they are not. You may need medical treatment if you get some of the
side effects.

Ask your doctor or pharmacist to answer any questions you may have.

Be sure that your doctor or pharmacist knows as soon as possible if you do
not feel well while you are taking PURI-NETHOL.

If you think PURI-NETHOL is causing you to have an allergic
(hypersensitivity) reaction, TELL YOUR DOCTOR IMMEDIATELY. Symptoms include:

• Severe skin rash, itching or hives.
• Swelling of the face, lips, mouth or throat.
• Difficulty breathing or swallowing.
• Fever.
• Low blood pressure (feeling dizzy and faint).

Tell your doctor if you notice any of the following:

• Jaundice (yellowing of the skin, caused by abnormal liver function)
• Nausea (feeling as if you are about to vomit)
• Vomiting
• Loss of appetite
• Skin rash
• Mouth ulcers
• Stomach ulcers which may make you feel as if you have an upset stomach and
  possibly a burning sensation in your chest and/or mouth
• A stiff and tender abdomen, possibly with chest pain (this may be caused
  by pancreatitis)
• Fever

Your doctor can prescribe helpful medication if you develop any of the above
side effects.

PURI-NETHOL can also have side effects which affect your kidney and liver
function, bone marrow and blood count. This may make you feel tired and weak. It
will also affect how well your blood clots. Your doctor will do regular blood
and urine tests to check for these problems.

Your doctor may also recommend that you change your dose of PURI-NETHOL if
you experience any of these side effects.

This is not a complete list of all possible side effects.

Tell your doctor if you notice anything else that is making you feel unwell,
even if it is not on this list.

Ask your doctor or pharmacist if you do not understand anything on this list.

Do not be alarmed by the above list of possible side effects. Many of them
are uncommon. You might not experience any of them.

After taking PURI-NETHOL

Storage

Keep your tablets in the bottle until it is time to take them.

If you take the tablets out of the bottle they may not keep well.

Keep PURI-NETHOL in a cool dry place where the temperature stays below 25°C.

Keep PURI-NETHOL away from light.

Do not store it, or take any other medicine, in a bathroom or near a sink.

Do not leave it in a car or on windowsills.

Heat and dampness can destroy some medicines.

Keep PURI-NETHOL where young children cannot reach it.

A locked cupboard at least one and a half metres above the ground is a good
place to store medicines.

Disposal

If your doctor tells you to stop taking PURI-NETHOL, or the medicine has
passed its expiry date, ask your pharmacist what to do with any tablets that are
left over.

Product description

What PURI-NETHOL looks like

PURI-NETHOL tablets are pale yellow. They are engraved with WELLCOME O4A
and a straight groove on one side and are unmarked on the other.

Ingredients

Mercaptopurine, Lactose, Hydrolysed starch, Maize, Stearic acid, Magnesium
stearate

Further information

Your doctor is the best person to give you advice on the treatment of your
illness. You may also be able to find general information about your illness and
its treatment from other sources, for example, books in public libraries and on
the Internet.