Of 75 HD-MTX courses for osteosarcoma, 62 courses were given with intravenous hydrations <3,000 mL/m2/day and the 13 remaining courses were given with intravenous hydrations ≥3,000 mL/m2/day. Twenty-three of 62 courses (59.0%) given with <3,000 mL/m2/day hydration were associated with elevated 72-hour plasma methotrexate levels ≥0.1 μmol/L. Interestingly, none of the HD-MTX courses given with ≥3,000 mL/m2/day hydration had elevated 72-hour plasma methotrexate levels (Figure 1). The above association between intravenous hydration and 72-hour plasma methotrexate levels was significant with a P-value of 0.007. In addition, the association between 72-hour plasma methotrexate levels and other associated factors including patients’ gender, HCO3, and urine specific gravity was analyzed and revealed no statistical significance. Similar to NHL, adverse complications were found more often in courses having elevated 72-hour plasma methotrexate levels ≥0.1 μmol/L (mucositis [8.7%] and liver toxicity [26.1%]) than in courses having 72-hour plasma methotrexate levels <0.1 μmol/L (mucositis [0%], bone marrow suppression [1.9%], and liver toxicity [15.4%]).


HD-MTX has been widely used as a key element in treating various cancer types. In childhood malignancies, this agent has been added to standard chemotherapeutic regimens for ALL, NHL, and osteosarcoma, and the outcomes of these cancer types have been dramatically improved compared with the pre-HD-MTX era.7,8,1013 Methotrexate is a cell cycle-specific chemotherapeutic agent and can be administered by infusion over few hours or continuous drip over 24 hours.17,26 The adverse complications of HD-MTX administration have been well recognized, such as various degrees of mucositis, bone marrow suppression, and renal and liver toxicities. Several methods have been introduced to prevent these complications, including the use of leucovorin in HD-MTX-containing regimens and the plasma methotrexate level-monitoring guidelines to optimize the dose and frequency of administered leucovorin. Aggressive hydration is another method used in HD-MTX regimens, but the optimal amount of intravenous hydration required to prevent its adverse complications remains unclear. Most research studies have mainly focused on the efficacy of the HD-MTX-containing regimens in cancer treatment; however, only a few of these have specifically looked at the safety of this chemotherapeutic agent and especially the method to prevent associated adverse complications. Herein, we have conducted a study specifically focusing on the most effective use of the intravenous strategy during HD-MTX administration, especially for institutions in developing countries with limited access to monitoring of plasma methotrexate level.

Thirty-seven pediatric oncology patients undergoing 165 courses of HD-MTX-containing chemotherapeutic regimens at Phramongkutklao Hospital were retrospectively reviewed. The patients were diagnosed with various cancer types requiring HD-MTX in their standard chemotherapeutic treatment regimens, including ALL, NHL, and osteosarcoma. All patients were given differing amounts of aggressive hydration and had plasma methotrexate level monitored. Important data were collected and analyzed, including 72-hour plasma methotrexate level, amounts of intravenous hydration, HCO3level, urine specific gravity, and duration of methotrexate infusion (4 vs 24 hours). The intravenous hydrations were administered between 2,400 and 3,600 mL/m2/day according to the recommendation from current pediatric protocols and were grouped and divided as <3,000 and ≥3,000 mL/m2/day.

In our study, patients with ALL tended to tolerate HD-MTX better than patients with NHL and osteosarcoma. Almost all patients with ALL had 72-hour plasma methotrexate levels <0.1 μmol/L consistent with complete clearance of HD-MTX. Only one patient presented a 72-hour plasma methotrexate level ≥0.1 μmol/L; however, the elevation of methotrexate level was not significantly correlated with patients’ gender, amount of intravenous hydration, HCO3, urine specific gravity, or duration of methotrexate infusion. In addition, this patient did not experience adverse complications from delayed methotrexate clearance. One possible explanation could be that the dose of HD-MTX in ALL protocols (1.5 g/m2) being lower than NHL and osteosarcoma protocols (3–12 g/m2) more easily caused the drug clearance among patients with ALL than among those with NHL and osteosarcoma. Although one-third of the patients with NHL experienced delayed clearance of HD-MTX, we could not identify a significant correlation between elevated 72-hour plasma methotrexate levels and other associated factors comprising patients’ gender, amount of intravenous hydration, HCO3, urine specific gravity, or duration of methotrexate infusion. Although our observation was not able to identify predictive factors for delayed methotrexate clearance, it revealed increased numbers of adverse complications including mucositis, bone marrow suppression, and renal toxicity among those patients experiencing delayed clearance of HD-MTX. This finding indicated the importance of monitoring plasma methotrexate levels among patients with NHL receiving HD-MTX regimen. All HD-MTX courses following osteosarcoma protocols were infused over 4 hours. The dose of HD-MTX was also noted to be higher than ALL and NHL protocols. Thirty percent of HD-MTX courses in osteosarcoma were associated with delayed methotrexate clearance. Interestingly, we found a significant association between intravenous hydration of <3,000 mL/m2/day and delayed methotrexate clearance. This finding indicated the importance of aggressive hydration ≥3,000 mL/m2/day in the HD-MTX course following osteosarcoma protocols. Furthermore, our observation again revealed the increased numbers of adverse complications, including mucositis and liver toxicity, among patients experiencing delayed clearance of HD-MTX. This observational finding also addressed the need to monitor plasma methotrexate levels among patients with osteosarcoma receiving HD-MTX regimens. Of note, no differences were observed in toxicities related to the timing in starting leucovorin rescue. Five (8.9%) patients who developed mucositis and five (8.9%) patients who experienced bone marrow suppression received ALL regimen (leucovorin started at 36 hours). However, 10 (9.1%) patients and 7 (6.4%) patients receiving NHL or osteosarcoma regimen (leucovorin started at 24 hours) developed mucositis and bone marrow suppression, respectively.

One limitation was that our study employed a retrospective design with a small sample size and the possibility of having other unknown confounding factors; therefore, a future randomized study enrolling a larger sample size might be of greater interest to affirm the usefulness of aggressive intravenous hydration among patients receiving HD-MTX regimens.

In summary, our study emphasized the requirement of aggressive intravenous hydration ≥3,000 mL/m2/day during HD-MTX administration following osteosarcoma protocols to achieve complete clearance of HD-MTX. In patients with osteosarcoma, aggressive hydration ≥3,000 mL/m2/day is highly essential. Moreover, this amount of fluid hydration is strongly recommended in institutions where plasma methotrexate levels are not available or results are not provided on the same day. No adverse complications were noted following ALL protocols with HD-MTX 1.5 g/m2. In addition, the administration of HD-MTX at this dose or lower might not require aggressive hydration ≥3,000 mL/m2/day as well as monitoring of plasma methotrexate level. None of the patients receiving aggressive hydration ≥3,000 mL/m2/day experienced signs or symptoms of volume overload; therefore, for all patients receiving this higher regime to increase the safety of HD-MTX administration would be more sensible.


This study was supported, in part, by grants from the Phramongkutklao Hospital and College of Medicine, Royal Thai Army. The authors would like to thank the patients and families for participating in the study.


The authors report no conflicts of interest in this work.

Chanchai Traivaree,1 Napakjira Likasitthananon,2 Chalinee Monsereenusorn,1 Piya Rujkijyanont1

1Division of Hematology/Oncology, Department of Pediatrics, Phramongkutklao Hospital and College of Medicine, Bangkok, Thailand; 2Department of Pediatrics, Lat Krabang Hospital, Bangkok, Thailand 


1. Herfarth HH. Methotrexate for Inflammatory Bowel Diseases – New Developments. Dig Dis. 2016;34(1-2):140–146.

2. Weinblatt ME. Methotrexate in rheumatoid arthritis: a quarter century of development. Trans Am Clin Climatol Assoc. 2013;124:16–25.

3. Howard SC, Mccormick J, Pui CH, Buddington RK, Harvey RD. Preventing and Managing Toxicities of High-Dose Methotrexate. Oncologist. 2016;21(12):1471–1482.

4. Stoller RG, Hande KR, Jacobs SA, Rosenberg SA, Chabner BA. Use of plasma pharmacokinetics to predict and prevent methotrexate toxicity. N Engl J Med. 1977;297(12):630–634.

5. Mitchell MS, Wawro NW, Deconti RC, Kaplan SR, Papac R, Bertino JR. Effectiveness of high-dose infusions of methotrexate followed by leucovorin in carcinoma of the head and neck. Cancer Res. 1968;28(6):1088–1094.

6. Abrey LE, Deangelis LM, Yahalom J. Long-term survival in primary CNS lymphoma. J Clin Oncol. 1998;16(3):859–863.

7. Moe PJ, Holen A. High-dose methotrexate in childhood all. Pediatr Hematol Oncol. 2000;17(8):615–622.

8. Cooper SL, Brown PA. Treatment of pediatric acute lymphoblastic leukemia. Pediatr Clin North Am. 2015;62(1):61–73.

9. Pui CH, Relling MV, Evans WE. Is mega dose of methotrexate beneficial to patients with acute lymphoblastic leukemia? Leuk Lymphoma. 2006;47(12):2431–2432.

10. PDQ® Pediatric Treatment Editorial Board. Childhood Non-Hodgkin Lymphoma Treatment (PDQ(R)): Health Professional Version. PDQ Cancer Information Summaries. Bethesda, MD: National Cancer Institute; 2002.

11. Woessmann W, Seidemann K, Mann G, et al. The impact of the methotrexate administration schedule and dose in the treatment of children and adolescents with B-cell neoplasms: a report of the BFM Group Study NHL-BFM95. Blood.2005;105(3):948–958.

12. Choeyprasert W, Pakakasama S, Sirachainan N, et al. Comparative outcome of Thai pediatric osteosarcoma treated with two protocols: the role of high-dose methotrexate (HDMTX) in a single institute experience. Asian Pac J Cancer Prev. 2014;15(22):9823–9829.

13. Isakoff MS, Bielack SS, Meltzer P, Gorlick R. Osteosarcoma: Current Treatment and a Collaborative Pathway to Success. J Clin Oncol. 2015;33(27):3029–3035.

14. Patiño-García A, Zalacaín M, Marrodán L, San-Julián M, Sierrasesúmaga L. Methotrexate in pediatric osteosarcoma: response and toxicity in relation to genetic polymorphisms and dihydrofolate reductase and reduced folate carrier 1 expression. J Pediatr. 2009;154(5):688–693.

15. Holmboe L, Andersen AM, Mørkrid L, Slørdal L, Hall KS. High dose methotrexate chemotherapy: pharmacokinetics, folate and toxicity in osteosarcoma patients. Br J Clin Pharmacol. 2012;73(1):106–114.

16. Fleisher M. Antifolate analogs: mechanism of action, analytical methodology, and clinical efficacy. Ther Drug Monit. 1993;15(6):521–526.

17. Goodsell DS. The molecular perspective: methotrexate. Stem Cells. 1999;17(5):314–315.

18. Rajagopalan PT, Zhang Z, Mccourt L, Dwyer M, Benkovic SJ, Hammes GG. Interaction of dihydrofolate reductase with methotrexate: ensemble and single-molecule kinetics. Proc Natl Acad Sci U S A. 2002;99(21):13481–13486.

19. Longo-Sorbello GS, Bertino JR. Current understanding of methotrexate pharmacology and efficacy in acute leukemias. Use of newer antifolates in clinical trials. Haematologica. 2001;86(2):121–127.

20. Khan ZA, Tripathi R, Mishra B. Methotrexate: a detailed review on drug delivery and clinical aspects. Expert Opin Drug Deliv. 2012;9(2):151–169.

21. Bhojwani D, Sabin ND, Pei D, et al. Methotrexate-induced neurotoxicity and leukoencephalopathy in childhood acute lymphoblastic leukemia. J Clin Oncol. 2014;32(9):949–959.

22. Ferrari S, Orlandi M, Avella M, et al. Effects of hydration on plasma concentrations of methotrexate in patients with osteosarcoma treated with high doses of methotrexate. Minerva Med. 1992;83(5):289–293.

23. Karremann M, Sauerbier J, Meier C, et al. The impact of prehydration on the clearance and toxicity of high-dose methotrexate for pediatric patients. Leuk Lymphoma. 2014;55(12):2874–2878.

24. Mikkelsen TS, Mamoudou AD, Tuckuviene R, Wehner PS, Schroeder H. Extended duration of prehydration does not prevent nephrotoxicity or delayed drug elimination in high-dose methotrexate infusions: a prospectively randomized cross-over study. Pediatr Blood Cancer. 2014;61(2):297–301.

25. Kinoshita A, Kurosawa Y, Kondoh K, et al. Effects of sodium in hydration solution on plasma methotrexate concentrations following high-dose methotrexate in children with acute lymphoblastic leukemia. Cancer Chemother Pharmacol. 2003;51(3):256–260.

26. Treon SP, Chabner BA. Concepts in use of high-dose methotrexate therapy. Clin Chem. 1996;42(8 Pt 2):1322–1329.

Source: Cancer Management and Research.
Originally published October 10, 2018.