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 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