Preloading magnesium attenuates cisplatin-associated nephrotoxicity: pilot randomized controlled trial (PRAGMATIC study)

Background: Cisplatin is one of the most potent chemotherapeutic drugs used in head and neck cancer treatment; however, nephrotoxicity is the major side-effect limiting usage. Magnesium supplementation has been reported to reduce risk in non-controlled studies. We investigated whether preloading with magnesium prevents nephrotoxicity with a low-dose weekly cisplatin regimen. Methods: We carried out a prospective pilot, single-blinded, randomized controlled trial to compare cisplatin-associated acute kidney injury (cis-AKI) and acute kidney disease (cis-AKD) between two groups: intravenous 0.9% NaCl 500 ml + KCL 20 mEq over 4 h pre-cisplatin 40 mg/m(2) weekly for 7-8 weeks (control group) compared with additional 16 mEq magnesium added to the saline infusion (Mg group) in 30 head and neck cancer patients. Cis-AKI was defined as an increased serum creatinine (SCr) >= 0.3 mg/dl within 7 days and cis-AKD is an increased SCr >= 0.3 mg/dl between last SCr and baseline pre-chemotherapy SCr. Results: The overall cisplatin tumor response rate and survival were comparable between groups. The baseline characteristics were comparable between groups, although SCr was lower in the controls (0.70 +/- 0.17 versus 0.87 +/- 0.17 mg/dl, P = 0.01). The incidence of cis-AKI was similar (4.6% versus 1.3%); however, the incidence of cis-AKD was higher for the control group (46.7% versus 6.7%, hazard ratio = 0.082, 95% confidence interval 0.008-0.79, P = 0.03). The time to develop cis-AKD was significantly shorter in the control group (P = 0.007). Conclusions: The magnesium-preloading regimen was safe and significantly showed a decreased incidence of cis-AKD. The encouraging results of our pilot study need to be confirmed in a large-scale randomized controlled trial.