Hypomagnesaemia ⬇️
Hypomagnesaemia for NCHDs in Irish hospitals: causes, Magnesium Sona/Verla oral replacement, IV MgSO₄ guidance, and refractory hypokalaemia.
🧠 Definition
- Typical Irish laboratory reference approx. 0.7–1.0 mmol/L.
- Replacement usually considered when <0.7 mmol/L; oral first line if ≥0.4 mmol/L and patient can swallow.
- Confirm unexpected results with a repeat sample.
🧾 Common causes
- GI loss: diarrhoea, high-output stoma, malabsorption, PPIs
- Renal loss: loop/thiazide diuretics, alcohol, aminoglycosides, cisplatin
- Redistribution: DKA treatment, refeeding, post-parathyroid surgery
- Often coexists with hypokalaemia and hypocalcaemia
🩺 Symptoms & ECG
- Often asymptomatic if mild
- Tremor, weakness, cramps, tetany
- Arrhythmias, prolonged QT, torsades (especially with low K⁺)
- Refractory hypokalaemia until Mg²⁺ corrected
🔍 Investigations
- Serum Mg²⁺; repeat to confirm
- Concurrent K⁺, Ca²⁺, phosphate, U&Es
- ECG if symptomatic, severe, or arrhythmia
- Review drugs and nutrition (refeeding risk)
💊 Management (Irish hospital practice)
- Follow your hospital pharmacy / medicines management hypomagnesaemia guideline (HSE sites use local DTC protocols).
- Oral first line when appropriate: Magnesium Sona tablets, Magnesium Verla sachets (max ~24 mmol/day divided).
- IV magnesium sulfate 50% w/v must be diluted — never give undiluted; rate and concentration limits apply.
- Correct hypokalaemia in parallel; monitor Mg²⁺ 12–24 h after IV doses.
- Symptomatic or severe: ECG monitoring; check reflexes and urine output with repeated IV magnesium.
- Renal impairment: pharmacy or nephrology advice before loading doses.
📈 Replacement tool
- Use the tool below — aligned with common Irish acute hospital guidance. Always confirm with local protocol.
Magnesium replacement
Irish hospital guidance from serum Mg²⁺ — confirm local DTC protocol
Typical Irish reference approx. 0.7–1.0 mmol/L. Oral Magnesium Sona / Verla first line when appropriate; IV MgSO₄ must be diluted. Low Mg²⁺ commonly causes refractory hypokalaemia — replace both as needed.
Note Template
Ready-to-use clinical note structure
🕒 08 / 10 / 2026 — 16:08 ATRP re: hypomagnesaemia Patient: [age] [sex] Admission Dx: [reason for admission] PMHx: [diuretics, PPI, alcohol, chemotherapy] 🧾 Hx: • Symptoms: tremor, weakness, cramps, arrhythmia • Concurrent hypokalaemia or hypocalcaemia • GI loss, alcohol, or diuretic use 🩺 Exam: • Vitals: HR __ BP __ RR __ Temp __ SpO₂ __ • Neuromuscular: reflexes, muscle strength • ECG if indicated 📋 Impression: Likely cause: [GI loss / renal loss / drugs / malnutrition] 📌 Plan: • Serum Mg²⁺, K⁺, Ca²⁺ — recheck after replacement • Oral or IV magnesium per protocol • Correct hypokalaemia if present • Monitor ECG if severe or symptomatic 👤 [Your Name], [Role] IMC: _______
Educational reference only. Medical disclaimer