AR3 - General Information

A pyrimidine nucleoside analog that is used mainly in the treatment of leukemia, especially acute non-lymphoblastic leukemia. AR3 is an antimetabolite antineoplastic agent that inhibits the synthesis of DNA. Its actions are specific for the S phase of the cell cycle. It also has antiviral and immunosuppressant properties. (From Martindale, The Extra Pharmacopoeia, 30th ed, p472)


Pharmacology of AR3

AR3 is an antineoplastic anti-metabolite used in the treatment of several forms of leukemia including acute myelogenous leukemia and meningeal leukemia. Anti-metabolites masquerade as purine or pyrimidine - which become the building blocks of DNA. They prevent these substances becoming incorporated in to DNA during the "S" phase (of the cell cycle), stopping normal development and division. AR3 is metabolized intracellularly into its active triphosphate form (cytosine arabinoside triphosphate). This metabolite then damages DNA by multiple mechanisms, including the inhibition of alpha-DNA polymerase, inhibition of DNA repair through an effect on beta-DNA polymerase, and incorporation into DNA. The latter mechanism is probably the most important. Cytotoxicity is highly specific for the S phase of the cell cycle.


AR3 for patients

This medicine is a type of chemotherapy for treating cancers of the
blood and certain other cancers. This medicine interfers with the
way cancer cells grow, Take your doses on a regular scheduled time
and DO NOT take this medicine more often than directed by your health
care provider. Finish the full course prescribed by your health care
provider. DO NOT stop taking this medicine unless diredted to do so
by your health care provider. While taking this medicine, you make
get infection more easily. Call your doctor if you get a fever, chills,
or sore throat. Drink plenty of water with this medicine.


AR3 Interactions

Reversible decreases in steady-state plasma digoxin concentrations and
renal glycoside excretion were observed in patients receiving beta-acetyl
digoxin and chemotherapy regimens containing cyclophosphamide, vincristine,
and prednisone with or without cytarabine or procarbazine. Steady state
plasma digitoxin concentrations did not appear to change. Therefore,
monitoring of plasma digoxin levels may be indicated in patients receiving
similar combination chemotherapy regimens. The utilization of digitoxin for
such patients may be considered as an alternative. Also flucytosine.


AR3 Contraindications

Cytarabine is contraindicated in those patients who are hypersensitive to the drug.


Additional information about AR3

AR3 Indication: For the treatment of acute non-lymphocytic leukemia, acute lymphocytic leukemia and blast phase of chronic myelocytic leukemia.
Mechanism Of Action: AR3 acts through direct DNA damage and incorporation into DNA. AR3 is cytotoxic to a wide variety of proliferating mammalian cells in culture. It exhibits cell phase specificity, primarily killing cells undergoing DNA synthesis (S-phase) and under certain conditions blocking the progression of cells from the G1 phase to the S-phase. Although the mechanism of action is not completely understood, it appears that cytarabine acts through the inhibition of DNA polymerase. A limited, but significant, incorporation of cytarabine into both DNA and RNA has also been reported.
Drug Interactions: Not Available
Food Interactions: Not Available
Generic Name: Cytarabine
Synonyms: Ara-C; Arabinocytidine; Arabinofuranosylcytosine; Arabinosylcytosine; AraC; Aracytidine; Aracytin; Aracytine; beta-Arabinosylcytosine; Beta-cytosine arabinoside; beta-D-Arabinosylcytosine; Citarabina [INN-Spanish]; Cytarabina; Cytarabin; Cytarabinoside; Cytarabinum [INN-Latin]; Cytosine 1-beta-D-arabinofuranoside; Cytosine beta-D-arabinoside; Cytosine arabinoside; Cytosine arabinose; Cytosine arabinofuranoside; Cytosine, beta-D-arabinoside; Cytosine-1-beta-D-arabinofuranoside; Cytosine-beta-arabinoside; Cytosine-beta-D-arabinofuranoside
Drug Category: Immunosuppressive Agents; Antimetabolites; Antineoplastic Agents; Antiviral Agents
Drug Type: Small Molecule; Approved; Investigational

Other Brand Names containing Cytarabine: AR3; Alexan; Arabitin; Arafcyt; Cytarbel; Cytosar; Cytosar-U; Depocyt; Depocyt (liposomal); Erpalfa; Iretin; Spongocytidine; Tarabine; Udicil;
Absorption: Less than 20% of the orally administered dose is absorbed from the gastrointestinal tract.
Toxicity (Overdose): Cytarabine syndrome may develop - it is characterized by fever, myalgia, bone pain, occasionally chest pain, maculopapular rash, conjunctivitis, and malaise.
Protein Binding: 13%
Biotransformation: Hepatic.
Half Life: 10 minutes
Dosage Forms of AR3: Powder, for solution Intrathecal
Suspension Intrathecal
Solution Intrathecal
Chemical IUPAC Name: 4-amino-1-[(2R,3S,4S,5R)-3,4-dihydroxy-5-(hydroxymethyl)oxolan-2-yl]pyrimidin-2-one
Chemical Formula: C9H13N3O5
Cytarabine on Wikipedia:
Organisms Affected: Humans and other mammals