Evaluation of the usefulness of protocol-based magnesium supplementation for hypomagnesemia in patients with advanced or recurrent colorectal cancer treated with panitumumab.

PURPOSE: Panitumumab (Pmab) is associated with a higher incidence and severity of hypomagnesemia compared to cetuximab, necessitating appropriate monitoring and management strategies. This study aimed to evaluate the efficacy of protocol-based magnesium (Mg) supplementation for treating hypomagnesemia in patients with advanced or recurrent colorectal cancer receiving Pmab.

METHODS

In this retrospective study, patients with colorectal cancer treated with Pmab between October 2010 and September 2023 were divided into two groups: the pre-protocol group (n = 30) and the post-protocol group (n = 30). The incidence of hypomagnesemia was compared between the groups. The hypomagnesemia management protocol included Mg supplementation at grade 1 (< LLN-1.2 mg/dL), initially with 20 mL (1 mEq/mL) of Mg sulfate injection. If Mg levels continued to decrease despite supplementation, the dose was increased to 40 mL (1 mEq/mL).

RESULTS

No significant difference was observed in the frequency of hypomagnesemia between the pre-protocol (56.7%, 17/30) and post-protocol (53.3%, 16/30) groups (P = 1.000). However, the incidence of grade 3 or higher hypomagnesemia was significantly lower in the post-protocol group than in the pre-protocol group (3.3%, 1/30 vs. 30.0%, 9/30; P = 0.012). The rate of deterioration from grade 1 to grade 3 or higher in patients who received Mg supplementation was significantly lower in the post-protocol group than in the pre-protocol group (6.3%, 1/16 vs. 60.0%, 9/15; P = 0.002).

CONCLUSION

Early Mg supplementation effectively reduced the incidence of severe hypomagnesemia, highlighting the utility of this protocol in managing hypomagnesemia in Pmab-treated patients.