Background Hypomagnesaemia is a common electrolyte abnormality, in the chronic state its symptoms are insidious and often non-specific. It is often undiagnosed and thus untreated. There is evidence from animal studies to suggest that magnesium is involved in pain control including an animal model of hyperalgesia which is induced by hypomagnesaemia. However the role of magnesium as an analgesic in patients is unclear. We report two cases of patients with advanced cancer who were admitted to a hospice for pain control which improved when their hypomagnesaemia was treated.

Cases Case 1 was a 73 year old man with non small cell lung cancer with metastatic bone pain. Case 2 was a 64 year old man with large cell neuroendocrine cancer with rib wall invasion.

Case Management Both patients were found on admission to have asymptomatic hypomagnesaemia and were treated with IV magnesium. Case outcome treatment for hypomagnesaemia resulted in an improvement in pain control such that analgesia was significantly decreased.

Conclusions The incidence of hypomagnesaemia in palliative patients is unknown although it is thought to be common. These cases suggest that treating hypomagnesaemia may improve patients’ pain control.