Case of Gitelman syndrome in which hypokalemia was exacerbated by the combination of adrenaline β₂ agonist and theophylline, and drug-induced QT prolongation occurred: initiatives for hypokalemia

Abstract

We report the case of a patient with Gitelman syndrome (GS) in which hypokalemia was exacerbated by the combination of adrenaline β₂ agonist and theophylline, and drug-induced QT prolongation occurred. A woman in her twenties was prescribed tulobuterol patches, theophylline and clarithromycin (CAM), and so on for an acute upper respiratory infection. After taking these medications, she developed increasing fatigue and weakness of the limbs, which was aggravated with prolonged usage. Upon admission to the Suita Tokushukai Hospital, hypokalemia (2.3 mEq/L) and QT prolongation (QTc, 0.523 sec) were detected. On the basis of physical findings and blood tests, it was inferred that the hypokalemia was attributed to GS, which was exacerbated by the combination of adrenaline β₂ agonist and theophylline. Additionally, it was suspected that CAM had contributed to the development of the prolonged QT interval. After discontinuance of all medications, the QT prolongation resolved. For GS, she has still been taking potassium agent even after she is discharged. Hypokalemia can result from a variety of causes, including drugs, and may lead to QT prolongation and other arrythmias. Thus, on the basis of our experience with this case, we developed a hypokalemia initiative, described herein.