Prospecto: information for the user

Citarabina Pfizer 100 mg powder and solvent for injectable solution and for infusion

Read this prospect carefully before starting to use this medicine, because it contains important information for you.

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

1. What is Citarabina Pfizer and what is it used for

2. What you need to know before starting to use Citarabina Pfizer

3. How to use Citarabina Pfizer

4. Possible adverse effects

5. Storage of Citarabina Pfizer

6. Contents of the package and additional information

Citarabina Pfizer is used in adults and in children. The active ingredient is citarabina.

Citarabina belongs to a group of medications called cytotoxics; these medications are used to treat acute leukemias (blood cancer due to having too many leucocytes in the blood), which includes prophylaxis and treatment of central nervous system involvement or CNS (meningeal leukemia). Citarabina interferes with the proliferation of cancerous cells, which are eventually destroyed.

Citarabina is also used to treat some type of chronic leukemia.

Induction of remission consists of an intensive treatment to reduce the extent of leukemia. When it works, the balance of blood cells is normalized to some extent and your health improves. This period of relative good health is called remission.

Maintenance treatment is a lighter treatment to make the remission that manifests last as long as possible. Low doses of citarabina are used to maintain leukemia under control and prevent it from relapsing.

Do not use Citarabina Pfizer:

• If you are allergic to citarabina or any of the other components of this medication (listed in section 6).
• If you are already taking medications that reduce the ability of the bone marrow to produce blood cells.

Warnings and precautions

Consult your doctor or pharmacist before starting to use Citarabina Pfizer.

• If your bone marrow is affected, treatment should be initiated under close medical supervision.
• Citarabina significantly reduces the production of blood cells in the bone marrow. This may increase the risk of infections or bleeding. Blood cell counts may continue to decrease up to a week after stopping treatment. Your doctor will perform periodic blood tests and examine your bone marrow if necessary.
• If you have or have had liver or kidney problems. During treatment with citarabina, your liver and kidney functions should be monitored. If your liver and/or kidneys do not function properly before treatment, citarabina can only be administered with maximum caution.
• If you have or have had gout, as citarabina may cause elevated uric acid levels.
• Severe and sometimes potentially life-threatening adverse effects may occur in the central nervous system, intestines, or lungs.
• If you are administered citarabina intravenously in combination with methotrexate intrathecally, as you may experience severe adverse effects in your nervous system, especially in young patients and adolescents.
• If you need to be vaccinated while on treatment with this medication, as live or attenuated virus vaccines should not be administered and the response to inactivated or killed vaccines may be reduced.

If you are in any of the cases listed above, consult your doctor before using Citarabina Pfizer.

Children and adolescents

The safety of this medication for use in infants has not been established.

Use of Citarabina Pfizer with other medications

Inform your doctor or pharmacist if you are using, have used recently, or may need to use any other medication.

• If you receive medications containing 5-fluorocytosine (a medication used to treat fungal infections).
• If you take medications containing beta-acetildigoxin, which is used to treat certain heart conditions.
• If you take gentamicin (an antibiotic for treating bacterial infections).
• If you are administered citarabina intravenously in combination with methotrexate intrathecally.

Pregnancy, breastfeeding, and fertility
If you are pregnant or breastfeeding, think you may be pregnant, or intend to become pregnant, consult your doctor before using this medication.

Pregnancy

You should not become pregnant while you or your partner are being treated with citarabina. If you are sexually active, you are recommended to use effective contraceptive methods to avoid pregnancy during treatment, regardless of your sex. Citarabina may cause congenital anomalies, so it is essential to inform your doctor if you think you are pregnant. Both men and women should use effective contraceptive methods during treatment and for 6 months after the last dose.

Contraception in fertile women

Women should always use effective contraceptive methods (contraception) to avoid pregnancy during treatment and for 6 months after the last dose.Consult your doctor about the contraceptive methods that are suitable for you and your partner.

Contraception in men

Patients with female partners in fertile ageshould always use highly effective contraceptive methodsto prevent pregnancy during treatment and for 3 months after the last dose.

Breastfeeding

You should stop breastfeeding during treatment with Citarabina Pfizer and for at least a week after the last dose or stop treatment, as this medication may be harmful to infants.

Fertility

Due to the potential risk of infertility after treatment, you should consider preserving semen before starting treatment with citarabina.

Driving and operating machinery
The effect of Citarabina Pfizer on the ability to drive vehicles or operate machinery is unknown. However, you should not drive if you experience any adverse event (nausea or vomiting) that may affect your ability to drive vehicles or operate machinery.

Citarabina Pfizer contains sodium

This medication contains less than 1 mmol of sodium (23 mg) per dose unit; it is essentially "sodium-free".

Method and Route of Administration

Citarabina Pfizershould only be administered under the supervision of a doctor with experience in the use of this type of treatment. Consult with your doctor or pharmacist if you have any doubts.

Citarabina Pfizer can be administered via intravenous injection as a rapid bolus or infusion, subcutaneously, and intrathecally.

In case of doubt, consult your doctor or nurse again.

Dosage

Your doctor will establish the dosage and duration of treatment as well as the most suitable route of administration for you, according to your condition, whether as an induction treatment or as a maintenance treatment, and according to your weight or body surface area and response to treatment.

Your doctor will indicate the number of treatment cycles you need.

During treatment, you will require frequent examinations, including blood tests. Your doctor will tell you how often you need to do this, and will be responsible for performing regular analyses of:

• Blood, to check if you have low blood cell counts that require treatment.
• Liver (also through blood tests) to check that citarabina does not negatively affect your liver function.
• Kidneys (also through blood tests) to check that citarabina does not negatively affect your kidney function.
• Uric acid levels in blood: citarabina could increase uric acid levels in the blood. If your uric acid levels are too high, another medication may be administered.

If You Receive More Citarabina Pfizer Than You Should

This medication will be administered in the hospital, so it is unlikely that you will receivemore citarabina than you should; howeversome of the known severe side effects of the medication, such as mouth ulcers, may appear, or your white blood cell and platelet count (which contributes to blood clotting) may decrease in the blood. In this case, you may need antibiotics or blood transfusions. Mouth ulcers can be treated to reduce discomfort during the healing process.

In case of overdose or accidental ingestion, consult your doctor or pharmacist immediately or call the Toxicological Information Service, phone: 91 562 04 20, indicating the medication and the amount ingested.

Like all medicines, Citarabina Pfizer may cause side effects, although not everyone will experience them.

The side effects of citarabina depend on the dose. The digestive tract is usually the most affected organ, as well as the blood.

Frequent side effects(may affect more than 1 in 10 patients) include:

• Infections, generalized infection, pneumonia.
• Reduction in the number of red blood cells, white blood cells, and/or platelets in the blood.
• Depression of the bone marrow, i.e., alteration of its immune system with loss of the ability to fight infections or diseases.
• Alteration of the normal function of the brain and cerebellum*, feeling of sleepiness*.
• Corneal disorder of the eye*.
• Accumulation of fluid in the lungs*, difficulty breathing*.
• Nausea, vomiting, diarrhea, inflammation or ulcers in the mouth or anus, abdominal pain.
• Liver function alteration.
• Eruption, hair loss.
• Fever, citarabina syndrome (consists of muscle pain, bone pain, and sometimes chest pain, fever, conjunctivitis, eruption, and discomfort, which usually appears 6-12 hours after administration and is treated with corticosteroids).
• Changes in the appearance of bone marrow cells and blood cells.

Frequent side effects (may affect up to 1 in 10 patients) include:

• Inflammation of a portion of the intestine with death of intestinal cells (necrotizing colitis)*.
• Ulcers on the skin, desquamation*.

Side effects of unknown frequency (cannot be estimated from available data) include:

• Severe allergic reaction.
• Inflammation at the injection site.
• Localized pus formation in the liver*.
• Retention of allergenic fluid.
• Loss of appetite.
• Change in personality*.
• Toxicity to the nervous system,inflammation of the nerves,headache,dizziness, coma*, alterations in the motor and sensory function of the peripheral nervous system* (when administered intrathecally), in children may appear a rare inflammatory disorder that causes damage to the material covering the nerves (leucoencephalopathy necrosis), paralysis of the legs and lower body (paraplegia), ascending progressive paralysis, progressive toxicity, convulsions.
• Conjunctivitis (infection in a part of the eye that may be accompanied by eruption),conjunctivitis with hemorrhage*, blindness (when administered intrathecally).
• Inflammation of the tissue covering the heart (pericarditis),slower or irregular heart rhythm(sinus bradycardia).
• Heart disease (cardiomyopathy)*, enlargement of the heart (cardiomegaly)*.
• Obstruction and inflammation of the blood vessel where the injection is made (thrombophlebitis).
• Throat pain, shortness of breath, inflammation of a part of the lung tissue*.
• Ulcer in the esophagus, inflammation in the esophagus, gastrointestinal ulcer*, presence of cysts in the intestinal wall*, peritonitis*, death of intestinal cells*, inflammation of the pancreas (pancreatitis).
• Yellowish discoloration of the skin, liver damage*, increase in bilirubin levels*.
• Urticaria, skin spots, itching.
• Urinary retention, kidney function alteration.
• Chest pain.
• Reaction at the injection site.
• Skin eruption on the palms of the hands and soles of the feet.

*Due solely to high doses of citarabina

Reporting of side effects

If you experience any type of side effect, consult your doctor, pharmacist, or nurse, even if it is a possible side effect that does not appear in this prospectus. You can also report them directly through theSistema Español de Farmacovigilancia de Medicamentos de Uso Humano: https://www.notificaram.es. By reporting side effects, you can contribute to providing more information on the safety of this medication.

Keep this medication out of the sight and reach of children.

This medication does not require special conservation conditions.

Do not use this medication after the expiration date that appears on the vial and label after CAD. The expiration date is the last day of the month indicated.

Do not use this medication if you observe that it is damaged or open.

Any unused or residue product will be disposed of in accordance with local regulations.

Composition of Citarabina Pfizer

• The active ingredient is citarabina.
• The other components are hydrochloric acid 10% (for pH adjustment), sodium hydroxide 10% (for pH adjustment) and water for injection preparations.

Appearance of the product and content of the packaging

Citarabina Pfizer is presented in a package that contains 1 vial with lyophilized powder and 1 ampoule with the solvent. The vial contains the lyophilized active ingredient, with a crystalline appearance, odorless and white.

Citarabina Pfizer 100 mg is presented in two formats: 1 vial + 1 ampoule and 100 vials + 100 ampoules (clinical packaging).

Only some package sizes may be commercially marketed.

Holder of the marketing authorization

Pfizer, S.L.

Avenida de Europa, 20 B

Business ParkThe Moraleja

28108 Alcobendas (Madrid)

Spain

Responsible for manufacturing

Actavis Italy S.p.A.

Viale Pasteur, 10

20014 Nerviano

Italy

Last review date of this leaflet: December 2022

The detailed and updated information on this medication is available on the website ofthe Spanish Agencyof Medicines and Medical Devices (AEMPS)http://www.aemps.gob.es/