Drug-induced hyponatraemia and possible related signals: Analysis of 659 cases reported to the Spanish Pharmacovigilance System and disproportionality analysis

There are increasing reports of drug-induced hyponatraemia. It can be serious and seems to most often affect women over 65 years of age who take more than 1 medication. The time to onset varies and can be very long, so patient monitoring should be continuous throughout treatment. Hydrochlorothiazide is the drug with the highest number of reported cases in our setting. In terms of disproportionate reporting, diuretics leads the list, followed by antiepileptics as oxcarbazepine and eslicarbazepine. Safety signals were found for several drugs, more plausibly for pregabalin and paliperidone, thus a possible association between these drugs and hyponatraemia/SIAD is identified. This signal must be further studied. Meanwhile healthcare professionals should pay attention to this possibility. The reporting of suspected ADRs is essential to understand the risks associated with medicines once they are on the market.