Revised: 01 May 2007
SYNONYMS: |
(a) A-ase,1 ASN-ase, Colaspase, Crasnitin,2 Elspar,3 L-asparagine amidohydrolase1
(b) Crisantaspasum,2 Krisantaspaasi, Krisantaspas
(c) PEG-L-asparaginase,2 Pegaspargasa, Pegaspargasum |
COMMON TRADE NAMES: |
(a) KIDROLASE®
(b) ERWINASE®
(c) ONCASPAR® |
CLASSIFICATION: antitumour antibiotic, cytotoxic4
Special pediatric considerations are noted when applicable, otherwise adult provisions apply.
MECHANISM OF ACTION:
Asparaginase hydrolyzes the amino acid L-asparagine to L-aspartic acid and ammonia.1,5 Asparagine is required for DNA synthesis and cell survival; however, most cells are capable of synthesizing asparagine from glutamine. Acute lymphoblastic leukemia (ALL) cells lack adequate levels of the required enzyme, asparagine synthetase, and cannot survive asparagine depletion. Asparaginase is cycle-specific for the G1 phase.6
There are three formulations of asparaginase available. These will be identified in the text as:
- Asparaginase (L-asparaginase isolated from E.coli )
- Erwinia asparaginase (L-asparaginase isolated from Erwinia chrysanthemi, previously called Erwinia carotova7)8
- Pegaspargase (L-asparaginase isolated from E.coli and attached to polyethylene glycol)
Erwinia asparaginase is serologically and biochemically distinct from asparaginase, although the antineoplastic activity and toxicity is similar. Pegaspargase has a longer half-life and decreased toxicity.
PHARMACOKINETICS:
|
Oral Absorption |
denaturation and peptidase digestion within GI tract1,9 |
|
Distribution |
diffuses poorly from the capillaries; approximately 80% of the dose remains within the intravascular space1; IM injection yields a much larger volume of distribution |
|
cross blood brain barrier? |
not detectable in cerebrospinal fluid (CSF), but CSF asparagine is depleted with systemic administration of any formulation10 |
|
volume of distribution |
asparaginase10: 3 L/m2 |
|
Erwinia asparaginase10: 5 L/m2 |
|
pegaspargase10: 2 L/m2 |
|
plasma protein binding |
no information found |
|
Metabolism |
unknown11 |
|
active metabolite(s) |
no information found |
|
inactive metabolite(s) |
no information found |
|
Excretion |
unknown, possibly using reticuloendothelial system11 |
|
urine |
asparaginase,6 pegaspargase12: trace amounts |
|
feces |
no information found |
|
terminal half life |
asparaginase IM13: 26-60 h |
|
Erwinia asparaginase IM13: 16 h |
|
pegaspargase IM13: 5.5-7 d |
|
clearance |
asparaginase10: 1.4 mL/min/m2 |
|
Erwinia asparaginase10: 3.4 mL/min/m2 |
|
pegaspargase10: 0.15 mL/min/m2 |
USES:
|
Primary uses: |
Other uses: |
|
*Leukemia, acute lymphoblastic a b c |
|
|
*Leukemia, acute lymphoblastic and hypersensitivity to asparaginase b c |
|
|
*Leukemia, acute myeloid a |
|
|
*Leukemia, chronic lymphocytic a |
|
|
*Lymphoma, Hodgkin’s a |
|
|
Lymphoma, non-Hodgkin’s14 a |
|
*Health Canada approved indication
a asparaginase
b Erwinia asparaginase
c pegaspargase
SPECIAL PRECAUTIONS:
Contraindications:
- Asparaginase is contraindicated in patients with a history of an allergy to asparaginase, or past or present pancreatitis.6
- Erwinia asparaginase is contraindicated in patients with a history of allergy to Erwinia asparaginase, or past or present pancreatitis.15
- Pegaspargase is contraindicated in patients with a history of allergy to pegaspargase, or past or present pancreatitis, or in patients who have experienced significant hemorrhagic or thrombotic side effects previously with other formulations of asparaginase.16
Cautions:
Significant hypersensitivity reactions may occur with all three formulations. During administration, resuscitation equipment and emergency drugs should be readily available.16,17 Reactions include rash, urticaria, edema, hypotension, respiratory distress, chills, fever and anaphylaxis, which may result in sudden death.1 An intradermal test dose is recommended for asparaginase but not for Erwinia asparaginase or pegaspargase.1,15,18
- Asparaginase has the highest frequency at 15-35%.6 Although skin testing is not completely reliable in predicting asparaginase hypersensitivity, an intradermal test dose is generally recommended prior to the first dose, or before restarting therapy after several days.1 While a positive skin test is often considered a contraindication to asparaginase treatment, some clinicians choose to use a desensitization procedure in positive reactors or before restarting therapy after several days. Anaphylactic reactions can occur within one-half to one hour following the first injection, including during skin testing, but occur mainly between the fifth and ninth injection.17 Risk factors include IV administration (decreased in IM or SC administration), prolonged therapy, high dose (> 6,000-12,000 units/m2), previous asparaginase therapy, and intermittent dosing.17
- Erwinia asparaginase may be used in patients who had an allergic reaction to asparaginase (see dosing guidelines).8 Up to 33% of patients who had an allergic reaction to asparaginase will also react to Erwinia asparaginase.8
- Pegaspargase is the least immunogenic, and may be used in patients who had an allergic reaction to asparaginase or Erwinia asparaginase (see dosing guidelines).17 Treatment-limiting reactions occurred in 9% of all patients, 14% of patients who had an allergic reaction to asparaginase, and 26% of patients who had an allergic reaction to both asparaginase and Erwinia asparaginase.19
Administration: Toxicity, other than hypersensitivity reactions, may be more severe when the drug is administered daily rather than weekly.1 For pegaspargase, IM administration is preferred over IV administration due to a lower incidence of hepatotoxicity, coagulopathy, gastrointestinal, and renal disorders.12
Carcinogenicity: No information found.
Mutagenicity: Not mutagenic in Ames test.16 Not known if asparaginase, Erwinia asparaginase or pegaspargase are clastogenic.
Fertility: No information found.
Pregnancy: FDA Pregnancy Category C.20 Animal studies have shown fetal risks and there are no controlled studies in women. Asparaginase, Erwinia asparaginase and pegaspargase should be given only if potential benefit justifies the potential risk to the fetus.
Breastfeeding is not recommended due to the potential secretion into breast milk.6
Special populations: Adults experience a higher incidence of toxicities, other than hypersensitivity reactions, compared to children.6 Patients can form asparaginase antibodies, which at least partially explains the high interpatient variability in asparaginase pharmacokinetics.11 Clinically, the formation of these antibodies may result in hypersensitivity reactions or may lead to a faster decrease in asparaginase activity.
SIDE EFFECTS:
The table includes adverse events that presented during drug treatment but may not necessarily have a causal relationship with the drug. Because clinical trials are conducted under very specific conditions, the adverse event rates observed may not reflect the rates observed in clinical practice. Adverse events are generally included if they were reported in more than 1% of patients in the product monograph or pivotal trials, and/or determined to be clinically important.21 When placebo-controlled trials are available, adverse events are included if the incidence is > 5% higher in the treatment group.
The table refers to asparaginase unless otherwise noted. Generally, the toxicities seen with Erwinia asparaginase are very similar to asparaginase.22 Pegaspargase toxicities have a later onset than comparable toxicities of asparaginase.12
ORGAN SITE |
SIDE EFFECT |
|
Clinically important side effects are in bold, italics |
|
allergy/immunology |
hypersensitivity reactions (anaphylaxis 15-35%,6 pegaspargase 1-5%12) |
|
blood/bone marrow/
febrile neutropenia |
anemia (<1%, nadir 14 days, recovery 21 days,6 pegaspargase (1-5%) nadir 14 days, recovery 21 days12) |
|
leucopenia (<1%, nadir 14 days, recovery 21 days,6 pegaspargase (1-5%) nadir 14 days, recovery 21 days12) |
|
thrombocytopenia (<1%, nadir 14 days, recovery 21 days,6 pegaspargase (1-5%) nadir 14 days, recovery 21 days12) |
|
cardiovascular (arrhythmia) |
tachycardia (pegaspargase: 1-5%)12 |
|
coagulation |
antithrombin III decreased (may be dose-limiting or fatal >10%)6 |
|
clotting factors V, VII, VIII, IX decreased (>10%)6 |
|
coagulation abnormalities (30%,22 Erwinia asparaginase 12%,19 pegaspargase 1-5%12) |
|
fibrinogen decreased (>10%,6 pegaspargase 1-5%12)21 |
|
protein C severe decrease (>10%)6 |
|
thromboplastin increased (pegaspargase 1-5%)12 |
|
constitutional symptoms |
fatigue (>10%,6 pegaspargase >5%12) |
|
night sweats (pegaspargase 1-5%)12 |
|
weight loss (0.1-1%)17 |
|
dermatology/skin |
extravasation hazard: nonvesicant23 |
|
injection site reaction, pain, itching, erythema, inflammation (pegaspargase 1-5%)12 |
|
gastrointestinal |
emetogenic potential: rare,24 pegaspargase rare12,19,24 |
|
abdominal cramps (70%,6 pegaspargase 1-5%12) |
|
anorexia (>10%,6 pegaspargase 1-5%12) |
|
diarrhea (0.1-1%,17 pegaspargase 1-5%12) |
|
stomatitis (1-10%)6 |
|
vomiting (<10%,24 pegaspargase > 5%12,19) |
|
hepatic |
hepatotoxicity (>0.01% and <0.1%,17 pegaspargase 1-5%12) |
|
hepatobiliary/pancreas |
pancreatitis acute (15%,6 pegaspargase >2%16) |
|
infection |
upper respiratory infection (pegaspargase 1-5%)19 |
|
sepsis6 |
|
metabolic/laboratory |
albumin decrease possibly with peripheral edema (<1%,1,6 pegaspargase19) |
|
alkaline phosphatase, transient increase (>10%,6 pegaspargase 1-5%12) |
|
azotemia (>10%)6 |
|
bilirubin, transient increase (>10%,6 pegaspargase 1-5%12) |
|
hyperglycemia requiring insulin (1.4%,22 pegaspargase 3%12) |
|
hyperuricemia (1-10%,6 pegaspargase 1-5%12) |
|
hypocholesterolemia (<1%)17 |
|
hypoglycemia (pegaspargase 1-5%)12 |
|
hypoproteinemia (pegaspargase 1-5%)12 |
|
transaminase, transient increase (>10%,6 pegaspargase 1-5%12) |
|
musculoskeletal |
arthralgia, myalgia (pegaspargase 1-5%)12 |
|
neurology |
coma (>25%)6 |
|
convulsions (10-60%,6 pegaspargase seizure (1-5%12) |
|
neurotoxicity (>10%,6 pegaspargase 1-5%12); generally reversible |
|
paresthesia (pegaspargase 1-5%)12 |
|
pain |
headache (pegaspargase 1-5%)12 |
|
pulmonary |
cough (>1%,6 pegaspargase 1-5%19) |
|
respiratory distress (>0.1% and <1%,17 pegaspargase 1-5%12) |
|
renal/genitourinary |
hematuria (pegaspargase 1-5%)19 |
|
renal dysfunction (pegaspargase 1-5%)19 |
|
renal failure, acute (<1%,6 pegaspargase19) |
|
urinary frequency (pegaspargase 1-5%)19 |
|
vascular |
thrombosis (<1%),12,19 pegaspargase (4%)12 |
Hypersensitivity reactions: see Special Precautions.
Coagulation abnormalities: Asparaginase may cause hemorrhagic and/or thrombotic events.25 These may occur after several weeks of therapy or after completion of therapy, and may be dose-related. Bleeding may be caused by a reduction in vitamin K-dependent clotting factors, a fall in fibrinogen levels, or decreased platelet aggregation to collagen.26 Venous thrombosis may be caused by decreased antithrombin III, proteins C and S, and increased thrombin.26 The majority of thromboses occur in the CNS.27 Hemostatic function should be monitored periodically during therapy.1 If coagulation abnormalities occur, the risk of recurrence with further asparaginase therapy is very low.25 Patients who require further asparaginase treatment may be treated prophylactically with fresh frozen plasma plus low dose heparin, or low dose heparin 3 to 4 days after therapy, or fresh frozen plasma plus antithrombin III concentrate.
Pancreatic effects: Impairment of pancreatic function occurs frequently and may be caused by decreased insulin synthesis or necrosis and inflammation of the cells of the pancreas.1 Pancreatitis can occur despite normal serum amylase, and can be fatal. Pancreatic function, including blood glucose, should be determined prior to and regularly monitored during therapy.1
Hyperuricemia may result from cell lysis by cytotoxic chemotherapy and may lead to electrolyte disturbances or acute renal failure.26 It is most likely with highly proliferative tumours of massive burden, such as leukemias, high-grade lymphomas and myeloproliferative diseases. The risk may be increased in patients with preexisting renal dysfunction, especially ureteral obstruction. Follow the local institutional treatment guidelines for hyperuricemia and tumour lysis syndrome.21
INTERACTIONS:
AGENT |
EFFECT |
MECHANISM |
MANAGEMENT |
|
cytarabine10 |
decreased effect of cytarabine when asparaginase is given immediately prior to or with cytarabine; enhanced effect of cytarabine when asparaginase is given after cytarabine |
suppression of asparagine concentrations |
refer to protocol by which patient is being treated21 |
|
methotrexate1 |
decreased effect of methotrexate when asparaginase is given immediately prior to or with methotrexate; enhanced effect of methotrexate when asparaginase is given after methotrexate |
suppression of asparagine concentrations |
refer to protocol by which patient is being treated21 |
|
serum thyroxine-binding globulin1 |
decreased total serum thyroxine concentration |
decreased synthesis of thyroxine-binding globulin in liver |
delay measurement until 4 weeks after asparaginase therapy |
|
vincristine1 |
increased vincristine neurotoxicity |
unknown |
refer to protocol by which patient is being treated21 |
SOLUTION PREPARATION AND COMPATIBILITY:
For basic information on the current brand used at the BC Cancer Agency, see Chemotherapy Preparation and Stability Chart in Appendix.
Additional information: Potential overfill in KIDROLASE® vials has been a cause of concern when calculating final concentration. The manufacturer states that, when reconstituted with 4 mL SWI, the final concentration is 2,500 IU/mL ± 250 IU/mL.28 The BC Cancer Agency considers the final concentration to be 2,500 IU/mL. For IM injection, asparaginase may be reconstituted with 2 mL NS to give a final concentration of 5,000 IU/mL,29,30 or 1 mL to give 10,000 u/mL.30 For high-dose therapy, the practice of reconstituting the 10,000 IU vial with 0.5 mL or 1 mL of NS has been used, but this is not supported by the literature and not recommended by the manufacturer.31
Compatibility of selected drugs with L-asparaginase29: The following are compatible via Y-site injection: methotrexate, sodium bicarbonate.
PARENTERAL ADMINISTRATION:
The table refers to asparaginase unless otherwise noted.
|
BCCA administration guideline noted in bold, italics |
|
Intradermal29 |
*test dose only |
|
Subcutaneous |
has been used, not generally recommended |
|
Erwinia asparaginase8: can be used |
|
Intramuscular (asparaginase, Erwinia asparaginase and pegaspargase)8,16,29 |
commonly used |
|
Direct intravenous |
into the tubing of a running infusion of preservative-free D5W or NS over > 30 minutes16,29 |
|
Erwinia asparaginase8: can be used |
|
pegaspargase: not given direct IV12 |
|
Intermittent infusion |
over > 30 minutes29 |
|
Erwinia asparaginase8: can be used |
|
pegaspargase: over 1-2 h16 |
|
Continuous infusion |
no information found |
|
Intraperitoneal |
no information found |
|
Intrapleural |
no information found |
|
Intrathecal |
has been used32 |
|
Intra-arterial |
no information found |
|
Intravesical |
no information found |
*MD or RN to administer test dose as per institutional policy.
DOSAGE GUIDELINES:
Refer to protocol by which patient is being treated. Numerous dosing schedules exist and depend on disease, response and concomitant therapy. Guidelines for dosing also include consideration of absolute neutrophil count (ANC) and liver function.21 Dosage may be reduced, delayed or discontinued in patients with bone marrow depression due to cytotoxic/radiation therapy or with other toxicities.
Adults:
|
|
|
BCCA usual dose noted in bold, italics |
|
|
Cycle Length: |
|
|
Intravenous/intramuscular asparaginase: |
n/a33: |
test dose: 2 units intradermally and observe for 1 h
then: 10,000 units IV daily on days 17-28 inclusive
(total dose 120,000 units)
|
|
|
n/a14: |
test dose: 2 units intradermally and observe for 1 h
then: 10,000 units/m2 IV daily on days 15, 17, 19, 22, 25, 28
(total dose 60,000 units/m2)
|
|
|
n/a6,17: |
200-1,000 units/kg/day IV or IM daily on days 1-28 inclusive
(total dose is 5,600-28,000 units/kg)
may be continued for an additional 14 days if complete remission is not obtained
(in this case: total dose 8,400-42,000 units/kg)
|
|
|
n/a17: |
400 units/kg IV or IM daily Monday and Wednesday 600 units/kg daily on Friday for 4 weeks
(total dose 4,800 units/kg)
may be continued for an additional 14 days if complete remission is not obtained
(in this case: total dose 5,600 units/kg)
|
|
|
n/a6: |
6,000-12,000 units/m2 IM daily on day 1
(total dose 6,000-12,000 units/m2)
|
|
|
2-3 weeks6: |
10,000-40,000 units IV daily on day 1
(total dose per cycle 10,000-40,000 units)
|
|
|
3 weeks6: |
5,000-10,000 units/m2/day IV daily on days 1-7 inclusive
(total dose per cycle 35,000-70,000 m2)
|
|
A test dose is often recommended prior to the first dose of asparaginase, or prior to restarting therapy, when there has been an interval of several days since the last dose.6 |
|
|
|
Intravenous/intramuscular Erwinia asparaginase: |
1 week8: |
6,000 units/m2 IV or IM for one dose on days 1, 3, and 5 for three weeks
(total dose per cycle 54,000 units/m2)
Therapy may be further intensified as per protocol.
|
|
When Erwinia asparaginase is used following a hypersensitivity reaction to asparaginase, dosing is different due to the different pharmacokinetic profiles.15 Generally, each dose of asparaginase should be replaced with a single dose of 20,000 units/m2 of Erwinia asparaginase. For intermittent therapy, Erwinia asparaginase treatment should be resumed at a low dose, 10 units/kg/day, and increased to the full dose over five days if tolerated.8 |
|
|
|
|
|
Intravenous/intramuscular pegaspargase: |
2 weeks16: |
2,500 units/m2 IV or IM for one dose on day 1
Note: pegaspargase is not to be given direct IV.
|
|
|
|
|
|
Concurrent radiation: |
not given21 |
|
|
|
|
|
Dosage in myelosuppression: |
modify according to protocol by which patient is being treated; if no guidelines available, refer to Appendix 6 "Dosage Modification for Myelosuppression" |
|
|
|
|
|
Dosage in renal failure: |
no adjustment required |
|
|
|
|
|
Dosage in hepatic failure: |
discontinue17 |
|
|
|
|
|
Dosage in dialysis: |
no information found |
|
|
|
|
Children:
|
|
Cycle Length: |
|
Intravenous/intramuscular
L-asparaginase or
Erwinia L-asparaginase: |
1 week10: |
6,000-10,000 units/m2 IV or IM for one dose on days 1, 3, and 5 |
|
|
|
|
|
Intravenous pegaspargase: |
1-4 weeks10: |
2,500 units/m2 IV or IM once daily on day 1
Note: often 2 or 3 syringes are required for a single IM dose.34
Note: pegaspargase is not to be given direct IV. |
|
|
|
|
References:
1. McEvoy GK. AHFS 2006 Drug Information. Bethesda, Maryland: American Society of Health-System Pharmacists, Inc.; 2006. p. 932-4.
2. Martindale - The Complete Drug Reference [database on the Internet]. Asparaginase. Thompson MICROMEDEX®, 2006. Available from http://www.micromedex.com. Accessed 4 October, 2006.
3. Merck & Co Inc. Elspar Product Monograph. West Point, Pennsylvania; 2000.
4. National Institute for Occupational Safety and Health (NIOSH). Preventing occupational exposures to antineoplastic and other hazardous drugs in healthcare settings. Cincinnati, Ohio: NIOSH - Publications Dissemination; September 2004. p. 31-40.
5. Graham ML. Pegaspargase: a review of clinical studies. Advanced Drug Delivery Reviews 2003;55(10):1293-302.
6. Anonymous. Asparaginase: Drug Information. In: Rose BD, editor. UpToDate Wellesley, Massachusetts: UpToDate 14.2; 2006.
7. Ettinger LJ, Ettinger AG, Avramis VI, et al. Acute Lymphoblastic Leukaemia A Guide to Asparaginase and Pegaspargase Therapy. Biopharmaceuticals 1997;1:30-9.
8. OPi SAS. Erwinase Product Monograph. Limonest, France; 2005.
9. Pizzo PA, Poplack DG. Principles and Practice of Pediatric Oncology. 4th ed. Philadelphia: Lippincott - Raven; 2002. p. 281-3.
10. Pizzo PA, Poplack DG. Principles and Practice of Pediatric Oncology. 4th ed. Philadelphia: Lippincott - Raven; 2002. p. 248.
11. Vieira Pinheiro JP. The best way to use asparaginase in childhood acute lymphatic leukaemia - still to be defined? bjh 2004;125:117-27.
12. Anonymous. Pegaspargase: Drug Information. In: Rose BD, editor. UpToDate Wellesley, Massachusetts: UpToDate 14.2; 2006.
13. Avramis VI, Panosyan EH. Pharmacokinetic/Pharmacodynamic Relationships of Asparaginase Formulations. Clin Pharmacokinet 2005;44(4):367-93.
14. Leukemia/Bone Marrow Transplantation Program of British Columbia. (NHL98-01) Treatment of Lymphoblastic Lymphoma. Vancouver, British Columbia: BC Cancer Agency; 10 May 2004.
15. Catherine Lambermont. Personal communication. Pharmacovigilance & Medical Information Manager, OPi SAS;September 2006.
16. Enzon Pharmaceuticals Inc. Oncaspar Product Monograph. Bridgewater, New Jersey; 2003.
17. OPi SAS. Kidrolase Product Monograph. Limonest, France; 2005.
18. Maharaj K. Raina, PhD. Personal communication. Director Medical Information, Enzon Pharmaceuticals;October 2006.
19. McEvoy GK. AHFS 2006 Drug Information. Bethesda, Maryland: American Society of Health-System Pharmacists, Inc.; 2006. p. 1166-8.
20. Briggs GG, Freeman RK, Yaffe SJ. Drugs in pregnancy and lactation. 5th ed. Baltimore, Maryland: Williams and Wilkins; 1998.
21. Kevin Song, MD. Personal communication. Hematologist, BMT/Leukemia Group Vancouver General Hospital, BC;December 2006.
22. Duval M, Suciu S, Ferster A, et al. Comparison of Escherichia coli-asparaginase with Erwinia-asparaginase in the treatment of childhood lymphoid malignancies: results of a randomized European Organisation for Research and Treatment of Cancer---Children's Leukemia Group phase 3 trial. Blood 2002;99(8):2734-9.
23. BC Cancer Agency Provincial Systemic Therapy Program. Provincial Systemic Therapy Program Policy III-20: Prevention and management of extravasation of chemotherapy. Vancouver, British Columbia: BC Cancer Agency; 1 February 2004.
24. BC Cancer Agency. (SCNAUSEA) Guidelines for Prevention and Treatment of Chemotherapy-induced Nausea and Vomiting in Adults. Vancouver, British Columbia: BC Cancer Agency; 1 November 2005.
25. Feinberg WM, Swenson MR, Feinberg WM, et al. Cerebrovascular complications of L-asparaginase therapy. Neurology 1988;38(1):127-33.
26. DeVita VT, Hellman S, Rosenberg SA. Cancer Principles & Practice of Oncology. 6th ed. Philadelphia: Lippincott Williams & Wilkins; 2001. p. 454-5.
27. Pizzo PA, Poplack DG. Principles and Practice of Pediatric Oncology. 4th ed. Philadelphia: Lippincott - Raven; 2002. p. 1190.
28. Robert Sarrazin, B Pharm. Personal communication. Consultant, OPi Inc. February 2005.
29. Trissel LA. Handbook on Injectable Drugs. 13th ed. Bethesda, Maryland: American Society of Health-System Pharmacists, Inc; 2005. p. 159-60.
30. Roberta Esau. Personal Communication. Pharmacist, British Columbia Children's Hospital, Oncology/Hematology Clinic;11 December 2006.
31. Robert Sarrazin, B Pharm. Personal communication. Consultant, OPi Inc. November 2005.
32. Dorr RT, Von-Hoff DD. Drug monographs. In: Dorr R, Von-Hoff D, editors. Cancer chemotherapy handbook. 2nd ed. Norwalk, Conneticut: Appleton and Lange; 1994. p. 201-8.
33. Leukemia/Bone Marrow Transplantation Program of British Columbia. (ALL89-01A) Treatment of Acute Lymphoblastic Leukemia Induction Cycle 1. Vancouver, British Columbia: BC Cancer Agency; 26 November 2004.
34. Roberta Esau. Personal Communication. Pharmacist, British Columbia Children's Hospital, Oncology/Hematology Clinic;15 October 2006.