MedDRA preferred term · low blood sodium

Hyponatraemia: adverse event reports recording this term

55,288 reports to FDA record it, 2004–2026; 0.3% of the database.

Read first · FDA's statement on these data

Adverse event reports submitted to FDA do not undergo extensive validation or verification. Therefore, a causal relationship cannot be established between product and reactions listed in a report. While a suspected relationship may exist, it is not medically validated and should not be the sole source of information for clinical decision making or other assumptions about the safety or efficacy of a product. Additionally, it is important to remember that adverse event reports represent a small percentage of total usage numbers of a product. Common products may have a higher number of adverse events due to the higher total number of people using the product. openFDA, FDA

FDA adds: "There is no certainty that the reported event (adverse event or medication error) was actually due to the product. FDA does not require that a causal relationship between a product and event be proven, and reports do not always contain enough detail to properly evaluate an event." The information in these reports "cannot be used to estimate the incidence of these events."

Do not rely on openFDA to make decisions regarding medical care. While we make every effort to ensure that data is accurate, you should assume all results are unvalidated.

Not medical advice. This site counts what was reported to FDA. Questions about a medicine or device belong with a pharmacist or clinician.

55,288
reports recording the term: 0.3% of all reports; 2,847
reports, 12 months to June 2026: 2,854 in the 12 months before; 97.3%
marked serious by the reporter: 57.4% across all reports; 9.6%
record death among outcomes, as reported: 9.1% across all reports

55,288 reports in FDA's adverse event database record the MedDRA term "Hyponatraemia" (in plain words, low blood sodium): 0.3% of all reports received between January 2004 and June 2026. Coders pick the term that best matches the reporter's description.

2,847 reports recorded it in the 12 months to June 2026, close to the 2,854 of the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. Of reports recording this term, 97.3% are marked serious, 9.6% include death among the outcomes and 77% include hospitalisation, as reported.

The drugs listed most often as suspect products in those reports are Furosemide, Hydrochlorothiazide and Omeprazole. That order mostly follows how many reports each drug has overall; the table also gives the term's share within each drug's own reports. FDA states that "a causal relationship cannot be established between product and reactions listed in a report" and that for any given report "there is no certainty that a suspected drug caused the event."

Reports by month, five years

FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases.

Drugs listed as suspect products in these reports

Drug	Class	Reports with this term	Share of the drug's own reports
Furosemide	Loop diuretic	2,929	6%
Hydrochlorothiazide	Thiazide diuretic	2,340	10.3%
Omeprazole	Proton pump inhibitor	1,910	3.1%
Lansoprazole	Proton pump inhibitor	1,448	5.4%
Ramipril	Angiotensin converting enzyme inhibitor	1,379	3.7%
Indapamide	Thiazide-like diuretic	1,183	21.3%
Sertraline	Serotonin reuptake inhibitor	1,161	2.6%
Cisplatin	Platinum-based drug	1,155	1.8%
Spironolactone	Aldosterone antagonist	1,129	5.4%
Carboplatin	Platinum-based drug	1,094	1.1%
Pantoprazole	Proton pump inhibitor	940	2.1%
Citalopram	Serotonin reuptake inhibitor	935	3.1%
Cyclophosphamide	Alkylating drug	878	0.6%
Mirtazapine	—	858	2.6%
Dexamethasone	Corticosteroid	833	0.6%
Prednisone	Corticosteroid	720	0.4%
Amlodipine	Calcium channel blocker	714	1.4%
Olanzapine	Atypical antipsychotic	709	1.5%
Lasix	Loop diuretic	692	5.5%
Escitalopram	Serotonin reuptake inhibitor	673	2.8%
Bevacizumab	Vascular endothelial growth factor inhibitor	643	1.2%
Gabapentin	Anti-epileptic agent	640	0.9%
Paclitaxel	Microtubule inhibitor	635	0.9%
Aldactone	Aldosterone antagonist	633	9.3%
Acetaminophen	Nonsteroidal anti-inflammatory drug	629	0.7%

Drugs with a page on this site, ordered by the number of their reports recording this term. The last column is the term's share within that drug's own reports, against 0.3% across the whole database. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."

By pharmacologic class

Class	Reports with this term	Share of class reports	Median drug in class
Proton pump inhibitor	5,749	1.2%	0.5%
Serotonin reuptake inhibitor	5,718	2.1%	1.4%
Loop diuretic	4,038	5.8%	5.5%
Corticosteroid	3,601	0.4%	0%
Atypical antipsychotic	3,441	0.5%	0.2%
Angiotensin 2 receptor blocker	3,192	1.3%	1.6%
Anti-epileptic agent	2,920	1.1%	0.5%
Kinase inhibitor	2,907	0.3%	0.3%
Platinum-based drug	2,636	1.1%	1.1%
Thiazide diuretic	2,535	7.6%	2.9%

Classes ordered by count. Class shares follow the class's overall report volume as much as anything else.

Patients in these reports

Patient age

Under 20.6%343

2 to 111.3%731

12 to 170.8%443

18 to 446.4%3,531

45 to 6420.2%11,151

65 to 7418.3%10,112

75 and over31.6%17,486

Age not given20.8%11,491

Patient sex

Female53.2%29,431

Male36.2%20,009

Not given10.6%5,848

Grey bar: all 20,646,523 reports in the database. 27.5% of these reports give the United States as the country.

Questions about "Hyponatraemia"

What does "Hyponatraemia" mean in an adverse event report?

In plain language: low blood sodium. It is a MedDRA preferred term, the dictionary FDA uses to code what a reporter described. The report's own description is not published by openFDA and is not shown here.

How many reports record hyponatraemia?

55,288 reports through June 2026 (0.3% of all reports), 2,847 of them in the latest 12 months.

Which drugs appear most often in these reports?

Furosemide (2,929), Hydrochlorothiazide (2,340), Omeprazole (1,910), Lansoprazole (1,448) and Ramipril (1,379). Drugs with many reports overall lead almost every term's list. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."

Does a drug appearing here mean it was responsible for this reaction?

No. FDA states that "a causal relationship cannot be established between product and reactions listed in a report" and that for any given report "there is no certainty that a suspected drug caused the event."

I have this symptom. What should I do?

This site cannot assess anyone. A pharmacist or clinician can; for an emergency, call the local emergency number. Nothing on this page is medical advice.

Where this comes from. Counts are built from the openFDA Drug Adverse Event (FAERS) bulk export released 28 Sep 2026, which holds reports FDA received through 30 Jun 2026. Drug names are as reported, resolved to the brand or generic name on the FDA label where openFDA's harmonisation matched them; classes are the pharmacologic class (EPC) from the label and the National Drug Code Directory of 17 Sep 2026. Terms are pooled across spelling and capitalisation variants of one MedDRA preferred term. No report narrative, lot number, patient detail or reporter identity is published. See the methodology and sources; FDA's record is authoritative, and corrections are handled within five working days.

Drug data (FAERS) through 30 Jun 2026; device data (MAUDE) through 31 Aug 2026. Not medical advice.