Information
Hypomagnesaemia is characterised by laboratory test results that indicate a low concentration of magnesium in the blood. Normal magnesium range = 0.70 –0.99 mmol/L. Many cancer drugs can lead to hypomagnesaemia for example Cisplatin, Carboplatin, Liposomal Doxorubicin, Cabozantanib, Cetuximab, and Panitumumab. Other drugs commonly used in cancer patients, e.g. diuretics, Gentamicin and other aminoglycoside antibiotics, can cause or contribute to low magnesium. Patients with severe treatment related diarrhoea are also at risk.
Most common symptoms are confusion, agitation, depression, hypertension, increased heart rate, cardiac arrhythmias, muscle weakness/tightness/tremors or twitches, convulsions drowsiness, fatigue and concomitant abnormalities of sodium, potassium, calcium and phosphate.
M.A, K.E & J.W. 12-02-26
Who to refer:
Any patient with a cancer diagnosis who is on treatment, within 6 weeks of treatment, has had immunotherapy within last 12 months who has confirmed hypomagnesaemia blood result or is symptomatic of suspected hypomagnesaemia
Who not to refer:
If in doubt please do not hesitate to call the on call oncology team.
How to refer:
Contact the Acute Oncology team at the Edinburgh Cancer Centre on 07798774842 or 0131 537 1000 and ask to speak to Acute Oncology team for oncology.
If patient has mild symptoms which may be related to Hypomagnesaemia please check magnesium level along with FBC and U&E’s. Oncology may advise magnesium aspartate replacement which is normally given in 6.5g sachets which contain 10mmol of magnesium. The usual dose is 10mmol two or three times daily (2-3 sachets per day). Bloods should be repeated after 1 week or in line with pre chemotherapy bloods.
All patients on or within six weeks of treatment should be encouraged to monitor symptoms and call The Cancer Treatment Helpline (CTH; 08009177711) with any treatment-related concerns. Please note, the CTH is a call operator service provided by NHS 24, who then refer on to an acute care specialist. They cannot give specialist advice.
If the patient has been assessed by a healthcare practitioner in Primary Care, and Oncology advice/input is felt to be required, the Primary Care clinician should call the Acute Oncology team at the Edinburgh Cancer Centre (based in the WGH) and discuss directly. The Acute Oncology team can be contacted during working hours (Mon-Fri 9-5) on 07798774842; If out of hours, please discuss with the Oncology Registrar On-Call via NHS Lothian Switchboard (0131 537 1000).
If the primary care clinician requires any further guidance on the suitability of referral to Acute Oncology, they can consult Pg 10 of the The UKONS Oncology/Haematology 24 Hour Triage Toolkit.
Note if a patient has presented to primary care for assessment, the patient should NOT be advised to call the CTH themselves to pass on this information or seek further advice.
Link to Acute Oncology Initial Management Guidelines:
UKONS | Acute Oncology Initial Management Guidelines (sundownsolutions.co.uk)
