Oral regimen for high dose methotrexate urine alkalinization: a systematic review and meta-analysis

Urine alkalinization prevents nephrotoxicity in patients receiving high-dose methotrexate (HDMTX). While the standard approach involves IV sodium bicarbonate, alternative oral bicarbonate regimens are crucial in drug shortages and outpatient settings. This study aims to review the efficacy and safety of such regimens.

PubMed, WOS, and Scopus were systematically searched using the PRISMA protocol for relevant studies involving human subjects, including randomized clinical trials, retrospective, prospective, cohort, case reports, and case series studies. There were no restrictions on language, time, or age group. Qualified and eligible papers were used to extract data on efficacy and safety indicators, and the final relevant records were assessed for quality using the Risk of Bias in Non-Randomized Studies—of Interventions (ROBINS-I) assessment tool.

12 studies with 1212 participants were included in the systematic review, with pooled data from 8 studies used for meta-analysis. No significant differences in mean differences (MDs) or odds ratio (OR) were found after the oral bicarbonate regimen, except for when urine pH fell to < 7 (MD: 0.91, 95% CI: 0.32, 1.5, P < 0.05) and the incidence of diarrhea (OR: 2.92, 95% CI: 1.69, 5.05, P < 0.05).

An oral bicarbonate regimen is a safe and effective way to alkalize HDMTX urine, providing a viable and cost-effective alternative to IV protocols. Further prospective multicenter studies are necessary.

Systematic review registration identifier: CRD42023379666.