For example , dexamethasone , hydrochlorothiazide , and theophylline can lower the level of potassium in the blood .
Other medications may increase the risk for a low level of potassium in the blood , thereby indirectly increasing the risk for QT prolongation .
Dexamethasone , hydrochlorothiazide , and theophylline can lower the level of potassium in the blood .
Other medications may increase the risk for a low level of potassium in the blood , thereby indirectly increasing the risk for QT prolongation .