cytarabine

Cytarabine is a drug with an antiviral action, but it is mainly used in anticancer chemotherapy.

Cytarabine - Chemical Structure

Cytarabine is also known as cytosine arabinoside or Ara-C.

From the chemical point of view, cytarabine consists of a molecule of cytosine (one of the nitrogenous bases that make up DNA) bound to a molecule of arabinose (a sugar).

Indications

For what it uses

The use of cytarabine is indicated for:

Induce remission in acute myeloid leukemia in adults and children;
Treatment of other proliferative forms of the white series (such as Burkitt's lymphoma, myeloid leukemia and lymphatic leukemia);
Treatment of lymphomatous meningitis. This pathology arises when lymphoma cancer cells invade the fluid or the membranes that line the brain and spinal cord.

Furthermore, cytarabine has antiviral activity, especially against herpesviruses and is effective in treating infections caused by them. However, due to its cytotoxicity (toxicity to cells), cytarabine is not often used for the treatment of viral infections.

Warnings

Cytarabine should be administered with extreme caution and under the strict supervision of a physician in patients suffering from pre-existing bone marrow depression caused by other drugs.

During treatment with cytarabine, patients' liver and kidney function must be constantly monitored. If patients suffer from liver problems prior to starting cytarabine therapy, this should be done with particular caution and under strict medical supervision.

Because of the myelosuppression (bone marrow suppression) that cytarabine can induce, patients being treated with the drug should not be vaccinated with live attenuated viruses, as their immune system would not be able to properly respond to the vaccine.

Patients who have undergone previous radiation therapy should inform their doctor before starting cytarabine therapy.

Cytarabine could cause side effects that could affect the ability to drive and / or operate machinery, so great care should be taken.

Interactions

Before starting treatment with cytarabine it is necessary to inform your doctor if you are taking - or have recently been taken - any of the following drugs:

5-fluorocytosine, an antifungal drug;
Drugs containing digitoxin or beta-acetyldigoxin, used to treat some heart conditions;
Gentamicin, an antibiotic;
Cyclophosphamide or vincristine, other anticancer drugs;
Prednisone, a corticosteroid.

In any case, it is still necessary to inform your doctor if you are taking - or if you have recently been - drugs of any kind, including medicines without a prescription and herbal and / or homeopathic products.

Side effects

Cytarabine may cause various types of side effects, although not all patients experience them. The type of side effects and the intensity with which they occur depend on the different sensitivity that each individual has towards the drug.

The main side effects that may occur during treatment with cytarabine are listed below.

Myelosuppression

Cytarabine may induce myelosuppression. This suppression, in turn, can lead to the onset of:

Anemia (decrease in hemoglobin blood levels), the main symptom of the onset of anemia is the feeling of physical exhaustion;
Leukopenia (decrease in blood levels of leukocytes), this leads to an increased susceptibility to the contraction of infections;
Plateletopenia (decrease in the number of platelets in the bloodstream), this leads to the appearance of bruising and abnormal bleeding with an increased risk of bleeding.

Gastrointestinal disorders

Treatment with cytarabine may cause:

Abdominal pain;
Nausea;
He retched;
Diarrhea;
Inflammation and / or ulceration of the oral cavity and anus;
Severe intestinal inflammation (necrotizing colitis);
Intestinal cysts.

When cytarabine is administered at high doses, even more serious gastrointestinal side effects may occur, such as pancreatitis, perforation, obstruction and / or gastrointestinal necrosis.

Cytarabine syndrome

During the treatment with cytarabine, the so-called cytarabine syndrome may occur, the symptoms of which are:

Temperature;
Nausea;
Bone pain;
Muscular pain;
Chest pain;
Conjunctivitis.

This syndrome can occur from six to twelve hours after starting treatment with the drug. To prevent or treat the symptoms that characterize it, your doctor may decide to prescribe steroidal anti-inflammatory drugs (corticosteroids).

Hepatobiliary disorders

Treatment with cytarabine may cause increased blood levels of liver enzymes and jaundice. Furthermore, when cytarabine is taken at high doses, abscesses or enlargement of the liver and blockage of the hepatic veins may occur.

Cardiovascular disorders

Cytarabine therapy can cause pericarditis, arrhythmias and cardiomyopathies.

Pathologies of the central nervous system

Treatment with cytarabine may favor the onset of:

Speech difficulties;
Attention difficulties;
Tremors;
Alteration of coordination;
Headache;
Dizziness;
Confusion;
Convulsions;
Coma.

Skin and subcutaneous tissue disorders

Cytarabine therapy may cause:

Erythema;
Skin eruptions;
Urticaria;
Itch;
Appearance of brown / black spots on the skin;
Alopecia;
Inflammation of the sweat glands;
Ulceration of the skin.

Eye disorders

Treatment with cytarabine may lead to:

Hemorrhagic conjunctivitis;
Visual disturbances;
photophobia;
Increased tearing;
Burning eyes;
Keratitis.

Lung and respiratory tract disorders

Cytarabine therapy may lead to the onset of:

Sore throat;
Inflammation and / or ulceration of the throat;
Breathing difficulties;
Pneumonia.

If cytarabine is administered at high doses, they may also occur:

Acute breathing difficulties;
Respiratory distress;
Pulmonary edema.

Other side effects

Other side effects that may occur during treatment with cytarabine are:

Allergic reactions, even serious, in sensitive subjects;
Temperature;
Nystagmus (at high doses);
Difficulty swallowing;
Loss of appetite;
vasculitis;
Inflammation at the injection site;
megaloblastosis;
Rhabdomyolysis;
Sepsis;
Hyperuricemia;
Paralysis of the legs and lower body (when cytarabine is administered near the bone marrow);
arthralgia;
Myalgia;
Chest pain;
Changes in renal function;
Urinary retention.

Overdose

In the event of an overdose of cytarabine, the symptoms that may occur consist of an exacerbation of the side effects caused by the same drug.

The pharmacological treatment in case of cytarabine overdose is supportive.

Action mechanism

Cytarabine exerts its cytotoxic action by interfering with DNA synthesis.

Cytarabine has a chemical structure very similar to that of deoxycytidine (one of the nucleosides that is normally part of DNA). Thanks to this characteristic, cytarabine replaces deoxycytidine and is inserted into the new DNA strand being formed. In this way, however, a sort of "error" is introduced which leads to the blocking of the synthesis of the same DNA and, consequently, to the arrest of the replication of the tumor cells.

Mode of Use - Posology

Cytarabine is available for intravenous administration as a solution for injection and / or infusion.

Cytarabine is administered by intravenous injection or infusion in the hospital and only by personnel specialized in the administration of anticancer agents.

When cytarabine is used for the treatment of lymphomatous meningitis, on the other hand, the injection must be made in the cerebrospinal fluid or in the lumbar sac. Also in this case, the drug will be administered by a doctor who specializes in the administration of anticancer chemotherapy.

The dose of drug to be administered and the duration of treatment must be established by the physician on an individual basis, depending on the body surface and the patient's condition and according to the type of therapy that must be undertaken (ie if one is on induction therapy or if you are on maintenance therapy).

Pregnancy and breastfeeding

Because of the possible damage that cytarabine can cause to the fetus, its use by pregnant women should be avoided.

Furthermore, patients of both sexes and patients' partners must use adequate contraceptive methods to prevent the onset of pregnancies, both during treatment with cytarabine and for a period of at least six months from the end of the same.

Cytarabine is excreted in breast milk and can cause serious damage to the newborn, therefore its use by breastfeeding mothers is contraindicated.