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Cytarabine - Cytosar®

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Usual Diluents

NS,  D5W,   D5NS,   LR

Dilution Data

Chemical Stability of Infusion Solutions:
Chemical stability studies were performed by a stability indicating HPLC assay on Cytarabine Injection in infusion solutions. These studies showed that when Cytarabine Injection was diluted with Water for Injection, 5% Dextrose Injection or Sodium Chloride Injection, in both glass and plastic infusion bags, 97-100% of the cytarabine was present after 8 days storage at room temperature.1

CYTARABINE injection, powder, lyophilized, for solution:
Solutions reconstituted with Bacteriostatic Water for Injection USP with benzyl alcohol may be stored at controlled room temperature, 15° to 30°C (59° to 86°F), for 48 hours. Discard any solutions in which a slight haze develops. Solutions reconstituted without a preservative should be used immediately.

Intravenous infusion: infuse over 1-3 hours or as a continuous infusion.  GI toxcity may be more pronounced with divided I.V. bolus doses than with continuous infusion.   Other:  May also be administered I.M., I.T., or SQ (<100 mg/mL). 2

IV Infusion volumes:  100 to 1000 mL  NS or D5W.
Note: Solutions containing bacteriostatic agents should not be used for the preparation of either high doses or intrathecal doses of cytarabine.2

Alternatively 3:
[Usual dose] [50-100mL NS* or D5W]  [15 - 60 minutes]
[Larger doses] [250mL NS* or D5W]  [over 1-3 hours]
   *Preferred solution

Stability / Miscellaneous
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Only physicians experienced in cancer chemotherapy should use Cytarabine Injection.

For induction therapy patients should be treated in a facility with laboratory and supportive resources sufficient to monitor drug tolerance and protect and maintain a patient compromised by drug toxicity. The main toxic effect of Cytarabine Injection is bone marrow suppression with leukopenia, thrombocytopenia and anemia. Less serious toxicity includes nausea, vomiting, diarrhea and abdominal pain, oral ulceration, and hepatic dysfunction.

The physician must judge possible benefit to the patient against known toxic effects of this drug in considering the advisability of therapy with Cytarabine Injection. Before making this judgment or beginning treatment, the physician should be familiar with the following text.

Cytarabine Injection, an antineoplastic, is a sterile isotonic solution for intravenous and subcutaneous use, which contains no preservative and is available in 20 mg/mL (1000 mg/50 mL) Pharmacy Bulk Package.

A Pharmacy Bulk Package is a container of a sterile preparation for parenteral use that contains many single doses. The contents are intended for use in a pharmacy admixture program and are restricted to the preparation of admixtures for intravenous infusion.

Each mL contains 20 mg Cytarabine, USP and the following inactive ingredients: sodium chloride 0.68% and Water for Injection q.s. When necessary, the pH is adjusted with hydrochloric acid and/or sodium hydroxide to a target pH of 7.4. Each vial contains approximately 5.82 mEq sodium.

Cytarabine is an odorless, white to off-white, crystalline powder which is freely soluble in water and slightly soluble in alcohol and in chloroform.

Cell Culture Studies: Cytarabine 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. Extensive chromosomal damage, including chromatoid breaks, have been produced by cytarabine and malignant transformation of rodent cells in culture has been reported. Deoxycytidine prevents or delays (but does not reverse) the cytotoxic activity.

Cellular Resistance and Sensitivity: Cytarabine is metabolized by deoxycytidine kinase and other nucleotide kinases to the nucleotide triphosphate, an effective inhibitor of DNA polymerase; it is inactivated by a pyrimidine nucleoside deaminase which converts it to the nontoxic uracil derivative. It appears that the balance of kinase and deaminase levels may be an important factor in determining sensitivity or resistance of the cell to cytarabine.

Human Pharmacology: Cytarabine is rapidly metabolized and is not effective orally; less than 20 percent of the orally administered dose is absorbed from the gastrointestinal tract.

Following rapid intravenous injection of cytarabine, labeled with tritium, the disappearance from plasma is biphasic. There is an initial distributive phase with a half-life of about 10 minutes, followed by a second elimination phase with a half-life of about 1 to 3 hours. After the distributive phase, more than 80 percent of plasma radioactivity can be accounted for by the inactive metabolite 1-β-D-arabinofuranosyluracil (ara-U). Within 24 hours about 80 percent of the administered radioactivity can be recovered in the urine, approximately 90 percent of which is excreted as ara-U.

Relatively constant plasma levels can be achieved by continuous intravenous infusion.

After subcutaneous or intramuscular administration of cytarabine labeled with tritium, peak-plasma levels of radioactivity are achieved about 20 to 60 minutes after injection and are considerably lower than those after intravenous administration.

Cerebrospinal fluid levels of cytarabine are low in comparison to plasma levels after single intravenous injection. However, in one patient in whom cerebrospinal levels were examined after 2 hours of constant intravenous infusion, levels approached 40 percent of the steady state plasma level. With intrathecal administration, levels of cytarabine in the cerebrospinal fluid declined with a first order half-life of about 2 hours. Because cerebrospinal fluid levels of deaminase are low, little conversion to ara-U was observed.

Immunosuppressive Action: Cytarabine is capable of obliterating immune responses in man during administration with little or no accompanying toxicity. Suppression of antibody responses to E. coli-VI antigen and tetanus toxoid have been demonstrated. This suppression was obtained during both primary and secondary antibody responses.

Cytarabine also suppressed the development of cell-mediated responses such as delayed hypersensitivity skin reaction to dinitrochlorobenzene. However, it had no effect on already established delayed hypersensitivity reactions.

Following 5-day courses of intensive therapy with cytarabine, the immune response was suppressed, as indicated by the following parameters: macrophage ingress into skin windows; circulating antibody response following primary antigenic stimulation; lymphocyte blastogenesis with phytohemagglutinin. A few days after termination of therapy there was a rapid return to normal.

Cytarabine in combination with other approved anticancer drugs is indicated for remission induction in acute non-lymphocytic leukemia of adults and children. It has also been found useful in the treatment of acute lymphocytic leukemia and the blast phase of chronic myelocytic leukemia. Intrathecal administration of cytarabine is indicated in the prophylaxis and treatment of meningeal leukemia.

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

Cytarabine Injection (non-preserved) can be administered by intravenous injection or infusion, subcutaneously, or intrathecally. However, the intent of this Pharmacy Bulk Package is for the preparation of solutions for IV infusion only. Intrathecal use of cytarabine requires the use of single-dose, unpreserved solutions only.

Cytarabine Injection is not active orally. The schedule and method of administration varies with the program of therapy to be used. While Cytarabine Injection may be given by intravenous infusion or injection, or subcutaneously or intrathecally, THE PURPOSE OF THE PHARMACY BULK PACKAGE IS FOR THE PREPARATION OF INTRAVENOUS INFUSIONS. Thrombophlebitis has occurred at the site of drug injection or infusion in some patients, and rarely patients have noted pain and inflammation at subcutaneous injection sites. In most instances, however, the drug has been well tolerated.

Patients can tolerate higher total doses when they receive the drug by rapid intravenous injection as compared with slow infusion. This phenomenon is related to the drug’s rapid inactivation and brief exposure of susceptible normal and neoplastic cells to significant levels after rapid injection. Normal and neoplastic cells seem to respond in somewhat parallel fashion to these different modes of administration and no clear-cut clinical advantage has been demonstrated for either.

In the induction therapy of acute non-lymphocytic leukemia, the usual cytarabine dose in combination with other anticancer drugs is 100 mg/m2/day by continuous IV infusion (Days 1-7) or 100 mg/m2 IV every 12 hours (Days 1-7).

The literature should be consulted for the current recommendations for use in acute lymphocytic leukemia.

Intrathecal Use in Meningeal Leukemia:
Cytarabine has been used intrathecally in acute leukemia in doses ranging from 5 mg/m2 to 75 mg/m2 of body surface area. The frequency of administration varied from once a day for 4 days to once every 4 days. The most frequently used dose was 30 mg/m2 every 4 days until cerebrospinal fluid findings were normal, followed by one additional treatment. The dosage schedule is usually governed by the type and severity of central nervous system manifestations and the response to previous therapy.

If used intrathecally, do not use a solution containing benzyl alcohol. This pharmacy bulk package is not intended to be used for the preparation of intrathecal doses.

Cytarabine given intrathecally may cause systemic toxicity and careful monitoring of the hemopoietic system is indicated. Modification of other anti-leukemia therapy may be necessary. Major toxicity is rare. The most frequently reported reactions after intrathecal administration were nausea, vomiting and fever; these reactions are mild and self-limiting. Paraplegia has been reported. Necrotizing leukoencephalopathy occurred in 5 children; these patients had also been treated with intrathecal methotrexate and hydrocortisone, as well as by central nervous system radiation. Isolated neurotoxicity has been reported. Blindness occurred in two patients in remission whose treatment had consisted of combination systemic chemotherapy, prophylactic central nervous system radiation and intrathecal cytarabine.

When cytarabine is administered both intrathecally and intravenously within a few days, there is an increased risk of spinal cord toxicity, however, in serious life-threatening disease, concurrent use of intravenous and intrathecal cytarabine is left to the discretion of the treating physician.

Focal leukemic involvement of the central nervous system may not respond to intrathecal cytarabine and may better be treated with radiotherapy.

Chemical Stability of Infusion Solutions:
Chemical stability studies were performed by a stability indicating HPLC assay on Cytarabine Injection in infusion solutions. These studies showed that when Cytarabine Injection was diluted with Water for Injection, 5% Dextrose Injection or Sodium Chloride Injection, in both glass and plastic infusion bags, 97-100% of the cytarabine was present after 8 days storage at room temperature.

This chemical stability information in no way indicates that it would be acceptable practice to infuse a cytarabine admixture well after the preparation time. Good professional practice suggests that administration of an admixture should be as soon after preparation as feasible.

Parenteral drugs should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit.

Handling and Disposal: Procedures for proper handling and disposal of anti-cancer drugs should be considered. Several guidelines on this subject have been published.1-7 There is no general agreement that all of the procedures recommended in the guidelines are necessary or appropriate.

Direction for Dispensing From Pharmacy Bulk Package: The 50 mL Pharmacy Bulk Package is for use in the Pharmacy Admixtures Service only. The vials should be inserted into the plastic handling device provided, suspended as a unit in the laminar flow hood.

A single entry through the vial closure should be made with a sterile dispensing set or transfer device. Transfer individual doses to appropriate intravenous infusion solutions. Use of a syringe with needle is not recommended. Multiple entries will increase the potential of microbial and particulate contamination.

The above process should be carried out under a laminar flow hood using aseptic technique. Care should be exercised to protect personnel from aerosolized drug (see DOSAGE AND ADMINISTRATION, REFERENCES). Discard any unused portion within 4 hours after initial closure entry.

Cytarabine Injection, PHARMACY BULK PACKAGE. Sterile, Isotonic Solution. Preservative Free. NDC No. 61703-303-46.

Cytarabine Injection 20 mg/mL (1000 mg) in a 50 mL flip-top vial (green cap), packaged individually. Store product at controlled room temperature, 15° - 30°C (59° - 86°F).
100 mg/5 mL in a single dose flip top vial (cool green cap) packaged in a carton of 5.
NDC No.: 61703-305-38

2 g/20 mL in a single dose flip top vial (green cap) packaged individually.
NDC No.: 61703-319-22
Cytarabine Injection. Sterile, Preserved Solution.
NDC No.: 61703-304-36.

Cytarabine Injection 20 mg/mL (500 mg/25 mL) in a multidose flip-top vial (red cap), packaged individually. Store at controlled room temperature, 15° - 30°C (59° - 86°F).

1)  [PACKAGE INSERT DATA] : cytarabine (CYTARABINE) injection, solution. Mayne Pharma (USA) Inc. Paramus, NJ 07652. Revision Date January 2004.

2) Solimando, Dominic A. Drug Information Handbook for Oncology: A Complete Guide to Combination Chemotherapy Regimens, 8th ed. Hudson, OH: Lexi-Comp, Inc.; 2010.

3) Cancer care Ontario. 620 University Avenue Toronto Ontario, Canada M5G 2L7.

Handling and Disposal: Recommendations for the Safe handling of Parenteral Antineoplastic Drugs, NIH Publications No. 83-2621. For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington , D.C.  20402. AMA Council Report, Guidelines for Handling Parenteral Antineoplastics, JAMA, 1985; 2.53 (11): 1590-1592. National Study Commission on Cytotoxic Exposure - Recommendations for Handling Cytotoxic Agents. Available from Louis P. Jeffrey, ScD., Chairman, National Study Commission on Cytotoxic Exposure, Massachusetts College of Pharmacy and Allied Health Sciences, 179 Longwood Avenue, Boston, Massachusetts 02115. Clinical Oncological Society of Australia, Guidelines and Recommendations for Safe handling of Antineoplastic Agents. Med J Australia, 1983; 1:426-428. Jones RB, et al: Safe Handling of Chemotherapeutic Agents: A Report from the Mount Sinai  Medical  Center. CA-A Cancer Journal of Clinicians, 1983; (Sept/Oct) 258-263. American Society of Hospital Pharmacists Technical Assistance Bulletin on Handling Cytotoxic and Hazardous Drugs. Am J. Hosp. Pharm, 1990; 47:1033-1049. Controlling Occupational Exposure to Hazardous Drugs. (OSHA Work Practice Guidelines), Am J. Health-Syst Pharm, 1996; 53: 1669-1685.

Cytarabine – Cytosar®