Cytarabine

Definition

Cytarabine (also known as ARA-C, and by the brand name Cytosar) is an anticancer agent that kills cancer cells. It is very frequently used with other anticancer drugs in the treatment of acute myelocytic leukemia (AML), lymphomas, and for leukemia and lymphoma affecting the surrounding membranes of the brain and spinal cord (meninges).

Purpose

There are two formulations of this drug: cytarabine, and cytarabine liposomal, where the drug is encapsulated in a molecule of lipid. Cytarabine is used to treat acute myelogenous leukemia, acute lymphocytic leukemia (ALL), chronic myelocytic leukemia (CML), central nervous system (CNS) leukemia affecting the membrane surrounding the brain and spinal cord, and Hodgkin's and non-Hodgkin's lymphoma (NHL). Cytarabine liposomal (brand name Depocyt) is primarily used to treat lymphoma involving the meninges (the membrane covering the brain and spinal cord).

Description

Cytarabine is a cytotoxic drug. This means that its task is to kill cancer cells. Cytarabine kills cells by interfering with the production of DNA.

Recommended dosage

The dose for cytarabine may be different depending on the protocol used by the physician. An example dose of cytarabine is 100 to 200 mg per square meter of body surface area per day for seven days as an intravenous (IV) medication.

High-dose cytarabine may be 2 to 3 grams per square meter of body surface area twice a day for three days. Cytarabine is also administered directly into the cerebral spinal fluid for lymphoma or leukemia involving the meninges. The dose is 5 to 75 mg per square meter of body surface area every two to seven days. The dose for cytarabine liposomal in the cerebral spinal fluid is usually 50 mg.

Precautions

Liposomal cytarabine not be given to patients with infections of the meninges, allergic reaction to cytarabine, or if the patient is pregnant.

Side effects

Side effects include fever in greater than 80% of patients, hair loss (alopecia), nausea and vomiting, diarrhea, ulcers of the mouth, decreased white blood cells (responsible for fighting infections), decreased platelets (responsible for blood clotting), decreased red blood cells (responsible for oxygenation of tissues), and decrease in liver function. Abdominal pain, loss of appetite, and a metallic taste in the mouth may develop, as may an allergic reaction. Tearing, eye pain, foreign body sensation in the eye, blurred vision, and sensitivity of the eyes to light occurs with high-dose cytarabine and may be prevented or relieved with corticosteroid eyedrops. Patients receiving high-dose cytarabine may also experience skin sloughing, redness and pain of the palms of the hand and soles of the feet, dizziness, headaches, drowsiness, confusion, personality changes, abnormal movements of the eye, loss of coordination, and in severe cases, loss of consciousness.

Although it is uncommon, one of the most serious side effects of cytarabine may involve sudden respiratory distress involving abnormal, shallow, and rapid breathing, which may progress to pneumonia.

High doses of cytarabine may trigger what is known as cytarabine syndrome, which consists of fever, muscle ache, bone pain, occasional chest pain, rash, inflammation of the membrane that covers the outer surface of the eye. This syndrome occurs six to 12 hours after the drug is given. Corticosteroids can treat this syndrome or prevent it from occurring.

Interactions

Drugs that decrease the function of the kidneys may increase the toxic side effects of cytarabine. Cytarabine may decrease the effect of digoxin and the antibiotics gentamicin and flucytosine. Prior to starting any new medications or herbal remedies, patients should consult with their physician, nurse, or pharmacist to prevent any drug interactions.

KEY TERMS

Cytotoxic drug

A medicine that kills (cancer) cells.

DNA

An acid found in all living cells that contains tiny bits of genetic information.

Lipids

Substances including fats, waxes, and related compounds that (with proteins and carbohydrates) constitute the principal structural components of living cells.