The UK Medicines Information group have provided excellent guidance on how to replace phosphate.

Clinical features

• Generally asymptomatic if mild
• Can cause many systemic features
  • CNS & MSK: weakness/myalgia, lethargy, confusion, seizures
  • Cardiorespiratory failure
  • Rickets/Osteomalacia if chronic

Causes

• Malabsorption
• D&V
• Refeeding syndrome

Investigations

• Check the calcium, U&Es, renal function

Treatment

• Use local guidelines or consider the information above
• Typically oral replacement for a mild deficiency (e.g. phosphate Sandoz) & IV therapies if moderate or severe
  • PO therapy risks diarrhoea
  • IV therapy via phosphate polyfusor has a large amount of potassium. Be careful of this contraindication in patients with hyperkalaemia

References & further reading

• Katzel, J.A., Vucuscu, R., Garcia, R., 2013. Wards 101 pocket clinician’s survival guide. Börm Bruckmeier Publishing.
• Lewis III, J. L., 2018. Hypophosphatemia. MSD Manual Professional Version.
• Mozingo, D.W. and Mason Jr, A.D., 2018. Hypophosphatemia. In Total Burn Care (pp. 280-286). Elsevier.

By Dr Shoaib Hussain