Mercaptopurine Qualix 50 mg tablets EFG

Package leaflet: Information for the user

Introduction

Package leaflet: information for the user

Mercaptopurine Qualix 50 mg tablets EFG

Read the entire leaflet carefully before you start taking this medicine, as it contains important information for you.

• Keep this leaflet, as you may need to read it again.
• If you have any questions, ask your doctor, pharmacist or nurse.
• This medicine has been prescribed for you only, and you should not give it to other people, even if they have the same symptoms as you, because it may harm them.
• If you experience any adverse effects, consult your doctor, pharmacist or nurse, even if these effects are not listed in this leaflet. See section 4.

Leaflet contents

1. What Mercaptopurine Qualix tablets are and what they are used for
2. What you need to know before taking Mercaptopurine Qualix tablets
3. How to take Mercaptopurine Qualix tablets
4. Possible side effects
5. How to store Mercaptopurine Qualix tablets
6. Contents of the pack and other information

1. What Mercaptopurina Qualix tablets are and what they are used for

This medicine contains the active substance mercaptopurine monohydrate, which belongs to a group of medicines called cytotoxic agents (also known as chemotherapy).

This medicine is used in the treatment of blood cancer, leukemia in adults, adolescents and children.

This medicine works by reducing the number of new blood cells produced by the body.

2. What you need to know before taking Mercaptopurina Qualix tablets

Do not take Mercaptopurina Qualix tablets:

If you are allergic to the active substance mercaptopurine monohydrate or to any of the other ingredients of this medicine listed in section 6.

Do not be vaccinated with the yellow fever vaccine while taking this medicine, as it may be fatal.

Warnings and precautions

Talk to your doctor or pharmacist before starting this medicine if:

• you have recently received a vaccine or are due to be vaccinated.
• while taking this medicine, administration of vaccines (such as the flu, mumps, or BCG vaccines) is not recommended until your doctor tells you it is safe. This is because some vaccines may cause you an infection if given while you are taking mercaptopurine.
• you have a condition that causes your body to produce insufficient amounts of an enzyme called TPMT (thiopurine methyltransferase deficiency), as your doctor may need to adjust your dose.
• you are allergic to a medicine called azathioprine (also used to treat cancer).
• you have kidney or liver problems, as your doctor will need to check that these organs are functioning properly.
• you have a genetic disorder called Lesch-Nyhan syndrome.
• you are planning to have a child. This applies to both men and women. This medicine may be harmful to sperm or eggs (see “Pregnancy, breastfeeding and fertility” below).

If you are receiving immunosuppressive treatment, taking this medicine may increase your risk of:

• tumors, including skin cancer. Therefore, when taking this medicine, avoid excessive exposure to sunlight, wear protective clothing, and use high-protection sunscreens.

• lymphoproliferative disorders:

• treatment with this medicine increases your risk of developing a type of cancer called lymphoproliferative disorder and other malignant tumors. When treatment includes multiple immunosuppressants (including thiopurines), this may lead to death.

• the combination of multiple immunosuppressants given simultaneously increases the risk of lymphatic system disorders due to viral infection (Epstein-Barr virus (EBV)-associated lymphoproliferative disorders).

Taking this medicine may increase your risk of:

• developing a serious condition called macrophage activation syndrome (excessive activation of white blood cells associated with inflammation), which usually occurs in people with certain types of arthritis.

Blood tests

Treatment with this medicine may affect your bone marrow. This means that the number of white blood cells, platelets, and (less frequently) red blood cells in your blood may decrease. Your doctor will perform blood tests daily during the initial phase of your treatment (induction) and at least weekly during the later phase (maintenance). These tests monitor the levels of these cells in your blood. If you stop treatment early enough, your blood cell levels will return to normal.

Liver function

Mercaptopurine is toxic to the liver. For this reason, your doctor will perform weekly liver function tests while you are taking this medicine. If you have pre-existing liver disease or are taking other medicines that may affect the liver, your doctor will perform tests more frequently. If you notice that the whites of your eyes or your skin turn yellowish (jaundice), inform your doctor immediately, as treatment may need to be stopped immediately.

Vitamin B3 deficiency (pellagra)

Inform your doctor immediately if you experience diarrhea, pigmented skin rash (dermatitis), or decreased memory, reasoning, or other thinking skills (dementia), as these symptoms may indicate vitamin B3 deficiency. Your doctor may prescribe vitamin supplements (niacin/nicotinamide) to treat this condition.

Infections

When receiving treatment with this medicine, your risk of viral, fungal, and bacterial infections is higher, and these infections may be more severe. See also section 4.

Before starting treatment, inform your doctor whether you have had chickenpox, shingles, or hepatitis B (a liver disease caused by a virus). If you suspect you have an infection, inform your doctor immediately.

NUDT15 gene mutation

If you have an inherited mutation in the NUDT15 gene (a gene involved in the breakdown of mercaptopurine in the body), you have a higher risk of infections and hair loss, and in this case your doctor may prescribe a lower dose.

Sun and ultraviolet light

When taking this medicine, you become more sensitive to sunlight and ultraviolet light. You should limit your exposure to sunlight and ultraviolet light, wear protective clothing, and use sunscreen with a high sun protection factor (SPF).

If you are unsure whether any of the above situations apply to you, consult your doctor or pharmacist before taking this medicine.

Children and adolescents

Low blood sugar levels (excessive sweating, nausea, dizziness, confusion, etc.) have occasionally been observed in children, particularly in children under six years of age or with low body mass index. If this occurs, consult your child's doctor.

Other medicines and Mercaptopurina Qualix tablets

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

In particular, inform your doctor or pharmacist if you are taking any of the following medicines:

• ribavirin (used to treat viral infections).
• other cytotoxic medicines (used to treat cancer).
• allopurinol, thiopurinol, oxipurinol, or febuxostat (used to treat gout).
• olsalazine or mesalazine (used to treat Crohn's disease and an intestinal disorder called ulcerative colitis).
• sulfasalazine (used to treat rheumatoid arthritis or ulcerative colitis).
• methotrexate (used to treat rheumatoid arthritis or severe psoriasis (skin)).
• infliximab (used to treat certain intestinal diseases [Crohn's disease and ulcerative colitis], rheumatoid arthritis, ankylosing spondylitis, or skin conditions [severe psoriasis]).
• warfarin and acenocoumarol (used to "thin" the blood).
• antiepileptic medicines such as phenytoin, carbamazepine. Blood levels of antiepileptics may need to be monitored and the dose adjusted if necessary.

Vaccinations during mercaptopurine treatment

If you are due to be vaccinated, speak with your doctor or nurse before doing so. This is because live vaccines (such as the polio, measles, mumps, and rubella vaccines) may cause you an infection if administered while you are taking this medicine.

Taking Mercaptopurina Qualix tablets with food and drink

You may take this medicine with food or on an empty stomach, but you must use the same method every day. You should take this medicine at least 1 hour before or 2 hours after consuming milk or dairy products.

Pregnancy, breastfeeding and fertility

Do not take mercaptopurine if you are planning to have a child without first consulting your doctor. This applies to both men and women. Mercaptopurine may be harmful to sperm or eggs. You and your partner should use effective contraception to prevent pregnancy while either of you is taking this medicine. Both men and women should use effective contraception for at least 3 months after receiving the last dose of treatment. If you are already pregnant, inform your doctor before taking mercaptopurine.

Mercaptopurine should not be handled by pregnant women, women planning to become pregnant, or women who are breastfeeding. Breastfeeding is not recommended during treatment with this medicine. Consult your doctor, pharmacist, or midwife.

Taking this medicine during pregnancy may cause intense and excessive itching without a skin rash. You may also experience nausea and loss of appetite at the same time, which may indicate a condition called cholestasis of pregnancy (a liver disease during pregnancy). Speak with your doctor immediately, as this condition may harm the fetus.

Driving and using machines

This medicine is not expected to affect your ability to drive or use machines, although no studies have been conducted to confirm this.

Mercaptopurina Qualix contains lactose

This medicine contains lactose. If your doctor has told you that you have an intolerance to certain sugars, consult him before taking this medicine.

3. How to take Mercaptopurine Qualix tablets

This medicine should only be prescribed by a specialist doctor experienced in the treatment of different types of blood cancer.

• While taking this medicine, your doctor will carry out regular blood tests to check the number and types of blood cells and to ensure your liver is functioning properly.
• Your doctor may also request additional blood and urine tests to monitor your kidney function and measure your uric acid levels. Uric acid is a natural substance produced by the body, and its levels may increase during treatment with mercaptopurine. Elevated uric acid levels can damage the kidneys. Your doctor may occasionally adjust your dose of mercaptopurine based on the results of these tests.
• Your doctor will calculate and adjust your dose based on your body weight or body surface area, blood test results, whether you are taking other chemotherapy medicines, and your kidney and liver function.

Always follow exactly the instructions given by your doctor or pharmacist. If you are unsure, consult your doctor or pharmacist again. It is important to take your medication at the correct time. The label on the container will indicate how many tablets you should take and how often. Consult your doctor, nurse, or pharmacist if this information is missing from the label or if you are uncertain.

The usual initial dose in adults and children is 2.5 mg per kg per day (or alternatively 50 to 75 mg per square meter [m²] of body surface area daily). Your doctor will calculate and adjust your dose based on your body weight, blood test results, whether you are taking other chemotherapy medicines, and your kidney and liver function.

Swallow the tablets whole. Do not chew the tablets. The tablets must not be split or crushed. If you or your caregiver handle split tablets, hands must be washed immediately.

Mercaptopurine Qualix with food and drink

You may take mercaptopurine with food or on an empty stomach, but the chosen method should be consistent every day. You must take the medicine at least 1 hour before or 2 hours after consuming milk or dairy products.

It is important to take mercaptopurine in the evening to ensure the medicine is more effective.

If you take more Mercaptopurine Qualix than you should

If you take more mercaptopurine than prescribed, or if someone else takes your medication by mistake, inform your doctor immediately or go to a hospital straight away. If you have any further questions about the use of this medicine, ask your doctor or pharmacist.

If you forget to take Mercaptopurine Qualix

If you forget to take a dose, inform your doctor. Do not take a double dose to make up for missed doses.

If you have any further questions about the use of this medicine, ask your doctor or pharmacist.

4. Possible adverse effects

Like all medicines, this medicine can cause adverse effects, although not everyone experiences them.

If you experience any of the following side effects, consult your specialist doctor or go to a hospital immediately:

• An allergic reaction, which may include:
  • Skin rashes
  • High temperature
  • Joint pain
  • Facial swelling
  • Skin nodules (erythema nodosum) (frequency not known)
• Any signs of fever or infection (sore throat, mouth ulcers, or urinary problems)
• Any unexpected bruising or bleeding, as this may indicate that you are producing an insufficient number of certain types of blood cells
• If you suddenly feel unwell (even if your temperature is normal), with abdominal pain and nausea or an urge to vomit, as this could be a sign of inflammation of the pancreas
• Yellowing of the whites of the eyes or the skin (jaundice)

Consult your doctor if you experience any of the following adverse effects, which may also occur with this medicine:

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

• Decrease in the number of white blood cells and platelets (can be detected in blood tests)

Common (may affect up to 1 in 10 people)

• Nausea or vomiting
• Decrease in red blood cells, which may cause tiredness, dizziness, or shortness of breath (called anaemia)
• Liver damage (can be detected in blood tests)
• Loss of appetite
• Inflammation of the pancreas (pancreatitis) in patients with inflammatory bowel disease

Uncommon (may affect up to 1 in 100 people)

• Joint pain
• Skin rash
• Fever
• Permanent liver damage (hepatic necrosis)
• Bacterial and viral infections, infections associated with neutropenia

Rare (may affect up to 1 in 1,000 people)

• Hair loss
• Mouth ulcers
• In men: temporary decrease in sperm count
• Allergic reaction causing facial swelling
• Various types of cancer, including blood, lymphatic, and skin cancers
• Inflammation of the pancreas (pancreatitis) in patients with leukaemia (blood cancer)

Very rare (may affect up to 1 in 10,000 people)

• A different type of leukaemia than the one being treated
• Ulcers in the intestine; symptoms may include abdominal pain and bleeding

Frequency not known (frequency cannot be estimated from available data)

• A rare type of cancer (hepatosplenic T-cell lymphoma, in patients with a condition called inflammatory bowel disease) (see section 2, Warnings and precautions)
• Sensitivity to sunlight causing skin reactions
• Decrease in blood sugar levels
• Burning or tingling sensation in the mouth or lips (oral mucosal inflammation, stomatitis)
• Cracked or swollen lips (cheilitis)
• Vitamin B3 deficiency (pellagra) associated with pigmented rash; diarrhoea, memory loss, or impaired reasoning and thinking abilities
• Decrease in blood clotting factors

Additional adverse effects in children

Cases of hypoglycaemia (excessive sweating, nausea, dizziness, confusion, etc.) have been reported in children who have received this medicine. However, most of the reported cases were in children under six years of age and with low body weight.

Reporting of adverse effects

If you experience any adverse effects, talk to your doctor, pharmacist, or nurse, even if they are possible adverse effects not listed in this leaflet. You can also report them directly through the Spanish Pharmacovigilance System for Human Medicines: https://www.notificaram.es. By reporting adverse effects, you can help provide more information on the safety of this medicine.

5. Storage of Mercaptopurine Qualix Tablets

Keep this medicine out of the sight and reach of children, preferably in a locked cabinet. Accidental ingestion may be fatal in children.

Store in the original packaging to protect from light.

Do not use this medicine after the expiry date stated on the packaging and blister after EXP. The expiry date refers to the last day of the month indicated.

Disposal of unused medicine and of all materials that have been in contact with it must be carried out in accordance with local regulations for cytotoxic agents.

Medicines must not be disposed of via wastewater drains or household waste. Return unused medicines and their packaging to the SIGRE point at your pharmacy. If you are unsure, ask your pharmacist how to dispose of medicines and packaging you no longer need. This will help protect the environment.

6. Contents of the pack and other information

Composition of Mercaptopurine Qualix tablets

The active substance is mercaptopurine monohydrate. Each tablet contains 50 mg of mercaptopurine monohydrate.

The other components are:

• Lactose
• Corn starch
• Maltodextrin
• Stearic acid (E-570)
• Magnesium stearate (E-572)

Appearance of the medicine and contents of the pack

This medicine consists of 6 mm, circular, yellowish tablets. The scored line is not intended for dividing the tablet.

This medicine is presented in an amber glass bottle with a polypropylene cap and child-resistant closure containing silica gel.

Pack sizes:

24 tablets in brown glass bottle
25 tablets in brown glass bottle
24 tablets / pack
25 tablets / pack
50 (2x25) tablets / pack

Only some pack sizes may be commercially available.

Marketing Authorization Holder and Manufacturer

Marketing Authorization Holder

Qualix Pharma, S.L.
C/Botànica, 137-139
08908 L'Hospitalet de Llobregat
(Barcelona), Spain

Manufacturer

Ardena Pamplona S.L.
Mocholi Industrial Estate, C/ Noain 1
Noain 31110 Navarra
Spain

This medicine has been authorized in EU Member States under the following names:

Germany: Mercaptopurin Holsten 50 mg Tabletten

Date of the most recent revision of this leaflet: October 2025

Detailed information on this medicine is available on the website of the Spanish Agency of Medicines and Health Products (AEMPS): http://www.aemps.gob.es/