Milk-alkali syndrome

Milk-alkali syndrome is the triad of hypercalcaemia, renal failure and metabolic alkalosis secondary to ingestion of large amounts of calcium and absorbable alkali.

Historically it was due to milk and alkali being given for peptic ulcer disease.  It is now becoming more prevalent again due to widespread use of calcium carbonate in the prevention of osteoporosis.  Some estimate it to now be the third most common cause of in-hospital hypercalcaemia.

Treatment is to stop the causative agent and hydrate the patient.

    

                                                                                                                                                                         

Reference:

 Medalov, B. Milk-alkali syndrome. Mayo Clin Proc. 2009; 84(3): 261-267.

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Hypercalcaemia

Calcium homeostasis is primarily controlled by parathyroid hormone and hydroxylated vitamin D. Parathyroid hormone is produced by the parathyroid gland and vitamin D is either indigested in the diet or synthesized in the skin via exposure to sunlight. The mechanisms of action are outlined in the diagram below:

Hypercalcaemia can result in the following signs and symptoms (beyond the classical ‘stones, bones, abdominal groans and psychic moans…’)

• Polyuria
• Polydipsia
• Renal stones
• Nausea and vomiting
• Anorexia
• Constipation
• Confusion
• Psychotic behaviour
• Headache
• Bone pain
• Hypertension (rare)

Causes of hypercalaemia:

• Main causes (>90%)
• Primary hyperparathyroidism
• Malignant disease
• Other causes
• Sarcoidosis
• Immobilisation
• Vitamin A or D toxicity
• Drugs – thiazide, lithium
• Thyrotoxicosis
• Addisons
• Phaeochromocytoma
• Granulomatous disease –TB, Wegeners granulomatosis, histoplasmosis
• Milk-alkali syndrome 

Malignant disease can cause hypercalcaemia due to:

• Bone involvement – boney mets - ‘bronchus, breast, byroid, brostate and bidney’ (AKA bronchus, breast, thyroid, prostate and kidney) and myeloma
• Parathyroid Hormone related Peptide (PTHrP) produced by tumour, especially squamous cell tumours such as lung, oesophagus and breast, renal and bladder tumours.

ECG changes seen in hypercalcaemia can include: short QT, bradycardia, bundle branch block or AV block

Treatment is:

• Treat cause
• Normal saline
• Pamidronate

Small print gem: Hypercalcaemia increases sensitivity to digoxin

References:

Makras, P. and Papapoulos, S. Medical treatment of hypercalcaemia. Hormones (Athens). 2009; 8(2): 83-95.

Mundy, G. and Gulse, T. Hormonal control of calcium homeostasis. Clin Chem. 1999; 45(8 Pt2): 1347-1352.

Ralston, S. Medical management of hypercalcaemia. Br J Clin Pharmacol. 1992; 34(1):11-20.

Shaw, Q. On aphorisms. Br J Gen Pract. 2009; 59(569): 954-955.

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