Continuous magnesium infusions in the management of systemic anti-cancer therapy-related hypomagnesaemia

Background Hypomagnesaemia is a relatively-common side effect of some systemic anti-cancer therapies (SACT). Oral and intravenous magnesium (given as injections or short infusions) have problems arising from their poor tolerability, and need for frequent administrations, respectively. Objective Assessing the effectiveness and safety of weekly continuous magnesium infusions (CMI) in the management of SACT-related hypomagnesaemia. Methods CMIs (initiated at 10 mmol/day and up-titrated subject to response) were prescribed to patients with ≥3 magnesium readings <0.5 mmol/L despite intravenous replacement with bolus-or-short-infusions (BSI). Efficacy (compared to BSI): (a) reduction in the number of moderate/severe hypomagnesaemia episodes, and (b) increase in mean magnesium serum levels.

non-occurrence of grade ≥3 toxicities (according to the common terminology criteria for adverse events v4). Results Three patients were treated (mean age: 62-years), pre-SACT levels were 0.629 ± 0.121 mmol/L.

(a) 1 versus 18 episodes; (b) 0.639 ± 0.093 mmol/L versus 0.533 ± 0.191 mmol/L. All comparisons were statistically significant in favour of CMI (p < 0.001). No magnesium-related grade ≥2 side effects were observed. Conclusion CMIs resulted in a marked reduction in the number of episodes of hypomagnesaemia and higher magnesium levels, with no significant side effects. CMIs represent a potential option for the management of SACT-related hypomagnesaemia, although further research in an expanded cohort is required.