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Management of hypokalaemia in Primary care-No current national guideline on management of hypokalaemia Focus here is on management in general practice using oral potassium supplement Sando-K® Reference range ( may vary between organizations ) see box above Hypokalaemia is usually well tolerated in otherwise healthy people but can be life threatening if severe Hypokalaemia increases the risk of morbidity and mortality in patients with CV disease Treatment is with potassium supplementation usually oral or IV
Identify and treat the underlying cause before starting / considering Potassium replacement. Take into account the following when considering potassium replacement. Patients known to suffer with underlying cardiac conditions as IHD , heart failure or LV hypertrophy- even mild hypokalaemia increases the likelihood of arrhythmia
Magnesium and potassium deficiencies appear related – consider checking Mg as presence of hypomagnesemia – makes correction of hypokalaemia very difficult
Exercise caution when replacing K+ in patients who are taking medications known to cause ↑↑ K conc e.g. potassium sparing diuretics as spironolactone , amiloride , triamterene , co-amilofruse , co-amilozide ACE inhibitors , ARBs Tacrolimus Ciclosporin Drugs containing potassium e.g potassium salts of penicillin
Severe renal impairment risk of hyperkalaemia due to impaired renal impairment seek adv from nephrology. Seek further advice if hypokalaemia remains unexplained
Maintaining a normal K+ level becomes particularly important in patients taking Digoxin or other anti-arrhythmic drugs ( arrhythmogenic potential of digoxin is enhanced by hypokalaemia ) Patients with hypoaldosternism due to ◘ renal artey stenosis ◘ liver cirrhosis ◘ nephrotic syndrome ◘ severe heart failure chronic diarrhoea – faecal loss of K+ TPN – patients who are nill by mouth
Dosage and duration of therapy will depend on existing deficit ongoing loss patients diet Larger doses would be required in patients with digitoxicity or diabetic ketoacidosis
Common SEs of oral administration include abdominal discomfort , diarrhoea , nausea and vomiting
Sando-K® is the most commonly used preparation in the UK for potassium replacement in asymptomatic patients with serum potassium between 2.5 and 3.5 mmol /L Each effervescent Sando-K® tablet contains 12 mmol potassium and 8 mmol of chloride Normal daily requirement of potassium is 50-100 mmol /L ( 1 mmol/ kg ) Advice to take oral potassium with plenty of fluids , with or after meals to avoid gastric irritation A drop of 1 mmol /L represents a loss of about 100-200 mmol /L of potassium from the body stores
References
- Management of Hypokalaemia Clinical Guideline V2.0 August 2019 Royal Cornwall Hospitals NHS Trust
- GGC Medicines Adult Therapeutics Handbook Management of hypokalemia
- Medicine compendium – Sando-K® UKMI guidance on the management of hypokalaemia via Leeds Teaching Hospital NHS Trust website