Addition of acetazolamide reduced time to urine alkalinization, allowing for earlier administration of high-dose methotrexate (HD-MTX). These findings, from a single-center, retrospective review, were published in Supportive Care in Cancer.

This study included 55 adult patients who had received at least 500 mg/m2 (mean dose, 5400 mg/m2) HD-MTX (in a total of 196 cycles) between 2016 and 2019 at the Augusta University Medical Center. Patients were pretreated to achieve urine alkalinization (pH ≥7) by intravenous (IV) sodium bicarbonate (NaHCO3) monotherapy (41 cycles), IV-NaHCO3 with acetazolamide (70 cycles), or by oral bicarbonate (PONaHCO3) with acetazolamide (76 cycles).

Treatment groups differed by age (P =.009), race (P =.002), cycle number (P =.037), HD-MTX dose (P =.006), acetazolamide dose (P =.001), and acetazolamide dose duration (P =.001).

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Time from first alkalinization dose to start of HD-MTX was longest for the monotherapy cohort (median, 7.5 hours; interquartile range [IQR], 5.6-18.3; P =.003) compared with IV dual therapy (median, 5.8 hours; IQR, 3.6-9.1) or oral dual therapy (median, 5.2 hours; IQR, 3.8-7.9).

Although the treatment groups differed for time to alkalinization, time from alkalinization to hospital release did not differ significantly (P =.054); monotherapy (median, 123.1 hours; IQR, 97.5-197.9), IV dual therapy (median, 123.7 hours; IQR, 102.4-150.6), and oral dual therapy (median, 125 hours; IQR, 99.4-170.3).

Limitations of this study included the lack of an oral monotherapy treatment and the fact that sodium bicarbonate dosage information were not available.

The conclusions drawn from these data were that although the addition of acetazolamide reduced time to alkalinization, overall hospital length of stay was not reduced.


Clemmons AB, Chase A, Duong P, Waller JL, Saunders K, Bryan L. Assessing the impact of adding acetazolamide to oral or intravenous sodium bicarbonate as compared with intravenous bicarbonate monotherapy as urinary alkalinization in adults receiving high-dose methotrexate. Support Care Cancer. Published online July 28, 2020. doi:10.1007/s00520-020-05646-z

This article originally appeared on Oncology Nurse Advisor