Therapeutic Handbook - GGC Prescribing

Management of Hypokalaemia (plasma K + < 3.5 mmol/L)Assessment / monitoring• Plasma potassiumGeneral management• Replace potassium losses• Identify and treat underlying cause where possible:- Loop / thiazide diuretics – consider combination with a potassium-sparing diuretic- Vomiting and diarrhoea- Intracellular potassium shifts, e.g. post-operation, coronary ischaemia, critical illness- Re-feeding- HypomagnesaemiaN.B. If hypokalaemia remains unexplained, more specialised investigations may be appropriate.Advice may be obtained from your local Biochemistry Department.Electrolyte DisturbancesDrug therapy / treatment optionsGeneral notes• Oral potassium chloride is the treatment of choice for most patients.Effervescent tablets (Sando-K ® ), which each contain 12 mmol of potassium and 8 mmol ofchloride, are preferable as modified release tablets (Slow-K ® ) may cause gastrointestinalulceration.• The dosage and duration of treatment depends on existing potassium deficit and whetherthere is continuing potassium loss.• Larger doses may be required especially in patients with digitoxicity or diabetic ketoacidosis.Advice is available from your local Biochemistry Department.• Potassium supplements should not be given in severe renal impairment or if plasma K + > 5.0mmol/L.• Caution should be used in patients with renal insufficiency or when ACE inhibitors orpotassium-sparing diuretics are being administered concomitantly.Continues on next pagePage 298