Recurrent Episodes of Hypokalaemia during Treatment with Inhaled Beta-2 Agonist Revealing Gitelman Syndrome, an Uncommon Clinical Entity

A 28-year-old female patient was hospitalized for mild–moderate hypokalaemia which was persistent despite discontinuation of beta-2 agonist bronchodilator treatment. Her past medical history was relevant for two episodes of severe hypokalaemia after active inhaled beta-2 agonist treatment for asthma crisis. Investigations revealed increased potassium in spot urine with a transtubular potassium gradient <4. A 24-hour urine analysis showed hypophosphaturia, hypocalciuria, hypomagnesuria and normal urine prostaglandins in favour of Gitelman syndrome. Oral potassium supplementation was started and genetic studies were recommended. LEARNING POINTS: An exhaustive aetiological work-up should be performed in young patients with persistent hypokalaemia after withdrawal of bronchodilators. Gitelman syndrome should be suspected in any patient with unexplained hypokalaemia, metabolic alkalosis, and a normal or low blood pressure.