Synopsis
Recognise symptomatic malignant hypercalcaemia, confirm biologically meaningful calcium elevation, restore volume safely, select antiresorptive and mechanism-specific treatment, monitor delayed response and align recurrence prevention with prognosis and goals.
- Suspect hypercalcaemia with new thirst, polyuria, dehydration, constipation, nausea, weakness, drowsiness or delirium, especially in breast, lung, renal, myeloma and advanced squamous cancers.
- Severity depends on symptoms, speed of rise, renal function and ECG as well as the number; adjusted calcium above 3.5 mmol/L is a medical emergency.
- First-line confirmation uses repeat adjusted calcium with albumin, or ionised calcium when albumin, acid-base state or critical illness makes correction unreliable.
- Check ECG, renal function, phosphate, magnesium, full blood count and medicines immediately; stop calcium, vitamin D, thiazide and other contributors where safe.
- Initial management is intravenous 0.9% sodium chloride titrated to volume depletion, comorbidity and urine output, with frequent reassessment for overload.
- Give an intravenous bisphosphonate after hydration and renal review; zoledronic acid usually works within several days, so clinical and biochemical monitoring must bridge the delay.
- Calcitonin can reduce calcium within hours in severe symptomatic disease but loses effect rapidly and is a short bridge, not durable monotherapy.
- Denosumab is an option for persistent or recurrent hypercalcaemia despite bisphosphonate, with substantial delayed hypocalcaemia risk, especially in kidney failure or vitamin D deficiency.
- Loop diuretics are not routine calcium-lowering therapy; use them only to treat fluid overload after adequate circulating volume is restored.
- Before repeated hospital treatment, discuss likely recurrence, anticancer options, expected symptom benefit and whether future episodes should be managed in hospital, community or comfort-focused care.
Key red flags
Reduced consciousness, seizure, aspiration or rapidly progressive delirium indicates severe neurological involvement.
Syncope, bradycardia, shortened QT or another arrhythmia requires monitored cardiac and electrolyte management.
Oliguria, rising creatinine or profound postural hypotension suggests significant renal and volume compromise.
Adjusted calcium above 3.5 mmol/L requires emergency assessment even if the symptom history is incomplete.
Breathlessness, crackles or rising oedema during rehydration indicates fluid overload and requires immediate rate reassessment.
Severe kidney disease magnifies both bisphosphonate nephrotoxicity and denosumab-related hypocalcaemia risk.
Persistent delirium after calcium improves requires a renewed search for infection, medicines, brain disease, retention and other causes.
Adjusted calcium above 3.5 mmol/L, coma, arrhythmia, profound dehydration or acute kidney injury requires urgent monitored treatment.
Investigation priorities
Confirm true elevation with concurrent albumin and use ionised calcium when correction is unreliable because of albumin, pH or critical illness.
Management branches
Hypercalcaemia is symptomatic, rapidly rising or above the severe threshold.
- Confirm calcium and albumin or ionised calcium, obtain ECG and renal-electrolyte baseline, stop contributing treatment and assess goals and escalation.
- Infuse 0.9% sodium chloride at an individual rate with frequent respiratory, fluid and urine review; treat genuine overload rather than routinely forcing diuresis.
- Give a renal-appropriate intravenous bisphosphonate and consider calcitonin for life-threatening symptoms while monitoring the delayed biochemical response.