• Keep this leaflet. You may need to read it again.
• If you have any further questions, ask your doctor, or pharmacist or nurse.
• This medicine has been prescribed for you only. Do not pass it on to others. It may harm them, even if their signs of illness are the same as yours.
• If you get any side effects, talk to your doctor, or pharmacist or nurse. This includes any possible side effects not listed in this leaflet. See section 4.

1. What Siklos is and what it is used for
2. What you need to know before you take Siklos
3. How to take Siklos
4. Possible side effects
5 How to store Siklos
6. Contents of the pack and other information

• if you are allergic to hydroxycarbamide or any of the other ingredients of this medicine (listed in section 6),
• if you suffer from severe liver disease,
• if you suffer from severe kidney disease,
• if you are myelosuppressed (if you have decreased production of red, white, or coagulating blood cells) as described in section 3 “How to take Siklos, Treatment follow-up”,
• if you are breast-feeding (see section “Pregnancy, breast-feeding and fertility”).

Talk to your doctor or pharmacist or nurse before taking Siklos

• if you have a liver disease,
• if you have a kidney disease,
• if you have leg ulcers,
• if you are taking other myelosuppressive medicines (decrease production of red, white, or coagulating blood cells) or receiving radiation therapy,
• if you have a known lack of vitamin B₁₂ or folate.

If you experience (or have experienced) any of the above, please tell your doctor. If you have any question, please ask your doctor or pharmacist or nurse.

Patients and/or parents or the legal responsible person must be able to follow directions regarding the administration of this medicine, their monitoring and care.

Tell your doctor or pharmacist if you are taking, have recently taken or might take any other medicines.

Information sharing is especially required for

• some antiretroviral medicines (those that inhibit or destroy a retrovirus such as HIV), e.g. didanosine, stavudine and indinavir (a drop in your white cell count may occur),
• myelosuppressive medicines (those that decrease production of red, white, or coagulating blood cells) and radiation therapy,
• some vaccines.

If you are pregnant or breast-feeding, think you may be pregnant or are planning to have a baby, ask your doctor for advice before taking this medicine.

Siklos is not recommended during pregnancy. Please contact your doctor immediately if you think you may be pregnant. The use of effective contraception is strongly recommended.

If you become pregnant or plan to become pregnant while taking Siklos, your doctor will discuss with you the potential benefits and risks of continuing using Siklos.

For male patients taking Siklos, if your partner becomes pregnant or plans to become pregnant, your doctor will discuss with you the potential benefits and risks of continuing using Siklos.

The active substance of Siklos passes into human breast-milk. You must not breast-feed while taking Siklos.

Hydroxycarbamide may decrease sperm production in male patients while they are being treated.

Some people may experience dizziness when using Siklos. Do not drive or use any tools or machines if you experience dizziness whilst taking Siklos.

Your doctor will tell you how much of Siklos to take each day and will describe the dose in whole, half or quarter tablets.

The prescribed dose of Siklos must be taken once daily, preferably in the morning before breakfast.

It can be taken with a glass of water or a very small amount of food.

If you cannot swallow the tablets, you can disintegrate them in water immediately before use:

• Place the required dose (preferably broken if Siklos 1 000 mg tablet is used) in a teaspoon and add some water.
• As soon as the tablet is disintegrated, swallow the content of the teaspoon. You can add a drop of syrup or mix the content with food to mask a possible bitter taste.
• Then drink a large glass of water or any other drink.

Siklos is a cytotoxic medicine that must be handled with care.

Any person, in particular pregnant women, who are not taking Siklos should avoid direct contact with the parts when breaking a tablet. Wash your hands before and after contact with the tablets.

In case the prescribed dose requires breaking the tablet in halves or quarters, this should be done out of the reach of food. Powder spilled from the broken tablet should be wiped up with a damp disposable towel which must be thrown out. For the storage of unused broken tablets, see section 5 “How to store Siklos”.

Your doctor will tell you how long to take Siklos.

When taking Siklos you will have regular blood tests and check your liver and kidney. Depending on the dose you take, these tests may be performed monthly or every two months.

Depending on these results your doctor will adjust your dose of Siklos.

If you take more Siklos than you should or if a child has taken any, contact your doctor or the nearest hospital immediately as you may need urgent medical treatment. The most common symptoms of overdose with Siklos are:

• Redness of the skin,
• Soreness (touch is painful) and swelling of the palms of hands and soles of feet followed by the hands and feet becoming scaly,
• Skin becoming strongly pigmented (locally changes of colour),
• Soreness or swelling in the mouth.

Do not take a double dose to make up for a forgotten tablet. Continue as normal when it is time to take the next dose as prescribed by your doctor.

Do not stop your treatment unless advised by your doctor.

• A severe infection,
• Tiredness and/or looking pale,
• Unexplained bruising (accumulation of blood under the skin) or bleeding,
• Unusual headache,
• Difficulties in breathing.

• Fever or chills,
• Feeling sick, or a general feeling of being unwell,
• Rash (itching red eruption of the skin),
• Ulcers or wounds on your legs,
• Sore (open skin infection) on your skin,
• Disorientation (confusion) and dizziness.

Very common side effects (may affect more than 1 in 10 people):

Low blood cell counts (myelosuppression), enlargement of red blood cells,

Absence or low amount of sperm in the semen (azoospermia or oligospermia). Siklos may hence decrease the ability of men to father children.

Common side effects (may affect up to 1 in 10 people):

Reduced number of red blood cells (anaemia), low platelet count, headache, skin reactions, inflammation or ulceration of the mouth (oral mucositis).

Uncommon side effects (may affect up to 1 in 100 people):

Dizziness, nausea, itching red eruption of the skin (rash), black nails (melanonychia), and hair loss.

Rare side effects (may affect up to 1 in 1 000 people):

Wounds on the legs (leg ulcers), and modification of liver function.

Very rare side effects (may affect up to 1 in 10 000 people) or unknown frequency (frequency cannot be estimated from the available data):

Inflammation of the skin causing red scaly patches and possibly occurring together with pain in the joints.

Isolated cases of malignant disease of blood cells (leukaemia), skin cancer in elderly patients, bleeding, gastrointestinal disturbances, vomiting, skin dryness, fever, absence of menstrual cycles (amenorrhoea), and weight gain.

If you get any side effects, talk to your doctor or, pharmacist or nurse. This includes any possible side effects not listed in this leaflet. You can also report side effects directly via the national reporting system:

United Kingdom (Northern Ireland)

or search for MHRA Yellow Card in the Google Play or Apple App Store

By reporting side effects you can help provide more information on the safety of this medicine.

• The active substance is hydroxycarbamide.
  Each Siklos 100 mg film-coated tablet contains 100 mg hydroxycarbamide.
  Each Siklos 1 000 mg film-coated tablet contains 1 000 mg hydroxycarbamide.
• The other ingredients are sodium stearyl fumarate, silicified microcrystalline cellulose and basic butylated methacrylate copolymer.

Siklos 100 mg film-coated tablets are off-white, oblong-shaped tablets with a break line on both sides. The tablet can be divided into two equal parts.

Each half of tablet is embossed “H” on one side.

Siklos 100 mg is supplied in plastic bottles containing 60, 90 or 120 tablets.

Siklos 1 000 mg film-coated tablets are off-white, capsule-shaped tablets marked with three score lines on both sides. The tablet can be divided into four equal parts.

Each quarter of tablet is embossed “T” on one side.

Siklos 1 000 mg is supplied in plastic bottles containing 30 tablets.

All pack sizes may not be marketed.