What the documents say about the kidneys
Kidney injury appears in the Saxenda® documents in three places: a warning about dehydration, a list of reports collected after approval, and guidance for people who already have reduced kidney function. [1][2][3]
| Item | What the document says | Source |
|---|---|---|
| Acute kidney injury | Post-approval reports, some needing dialysis; most after dehydrating stomach reactions | US 5.6, 6.2 [1] |
| Acute renal failure; renal impairment | Rare (1 to 10 in 10,000) | EU Table 4 [2] |
| Dehydration | Uncommon; more likely at the start of treatment | EU Table 4 and leaflet [2] |
| Mild or moderate kidney impairment | No dose change; may have more stomach effects | EU 4.2, 4.8 [2] |
| Severe kidney impairment or kidney failure | Not recommended (EU, Canada); limited experience (US) | EU 4.2; Canada 7; US 8.6 [1][2][3] |
The dehydration chain
The US label explains that most of the reported kidney injuries happened in people who had nausea, vomiting or diarrhoea that led to dehydration, and asks for kidney function to be checked in anyone reporting such reactions, especially during dose initiation and escalation. [1] Those are exactly the weeks when stomach effects are most common: in the trials, 67.9% of adults on Saxenda® reported some digestive complaint and 4.8% a severe one. [1][3]
One trial case shows the chain in action: a person on Saxenda® developed low blood pressure together with digestive side effects and kidney failure. [1] Liraglutide is not removed mainly by the kidneys; only small amounts of its breakdown products appear in urine. [1]
The Canadian monograph adds that kidney problems have been reported in association with nausea, vomiting, diarrhoea or dehydration and may sometimes need dialysis, and asks for caution when starting or raising the dose in people with kidney insufficiency. [3]
What studies and case reports add
The LEADER trial followed 9,340 people with type 2 diabetes and high cardiovascular risk for a median of 3.84 years on liraglutide 1.8 mg, the Victoza® dose, or placebo. Kidney adverse events were similar in both groups, including acute kidney injury at 7.1 and 6.2 events per 1,000 patient-years, and new persistent protein in the urine was less common on liraglutide. [4] The dose and population differ from Saxenda®, so the result does not transfer directly.
A 2024 case report described a 17-year-old with severe obesity who developed acute kidney injury and liver injury after three months on the lowest liraglutide dose, with marked loss of appetite and weight loss; both resolved within a month of stopping. [5] A single case cannot show how often this happens, but it is a reminder that teenagers are included in the warning.
Pharmacokinetic studies found liraglutide exposure was not higher in people with kidney impairment; it was 19% to 35% lower than in healthy people. [1]
Who may be more exposed
- People with vomiting or diarrhoea that goes on, especially in the first weeks while the dose is climbing. [1]
- People with existing kidney disease, who may also have more digestive side effects on Saxenda®. [2][3]
- Older adults, who may have more stomach effects according to the EU and Canadian documents, and who MedlinePlus lists among people at higher risk of dehydration. [2][3][7]
- People taking medicines that MedlinePlus lists as possible causes of kidney injury, such as anti-inflammatory painkillers and some blood pressure medicines. [6]
Signs of kidney trouble
MedlinePlus lists the symptoms of acute kidney failure as including little or no urine, swelling of the legs, ankles or feet, tiredness, confusion, nausea or vomiting that may last for days, a metallic taste, easy bruising, flank pain and shortness of breath. [6] The EU leaflet names reduced urine, a metallic taste and easy bruising as possible signs on Saxenda®. [2]
Dehydration usually comes first. Early signs include thirst, a dry mouth, passing little urine, darker urine and headache; severe signs include very dark or no urine, confusion, dizziness and a fast heartbeat. [7]
Urinary tract infection was also reported a little more often on Saxenda® than on placebo, at 4.3% against 3.1%, and is a separate issue from kidney injury. [1]
What the leaflets ask you to do
The Medication Guide asks you to drink fluids to help reduce the chance of dehydration and to tell your provider straight away about nausea, vomiting or diarrhoea that does not go away. [1] The US counselling section adds that patients should be told the signs of acute kidney injury and report them promptly. [1] The EU and Canadian leaflets both stress drinking plenty of fluids to avoid dehydration at the start of treatment. [2][3]
MedlinePlus advises sipping water, sucking ice cubes or drinking fluids with electrolytes to treat dehydration, and not taking salt tablets. [7] For prevention of kidney injury it lists keeping conditions such as diabetes and high blood pressure under control and avoiding medicines that can harm the kidneys. [6]
Before starting Saxenda®, tell your prescriber about any kidney problems. [3] Whether and how kidney function is checked is their decision.
Saxenda® and Victoza® are registered trademarks of Novo Nordisk A/S. PepLabo is not affiliated with or endorsed by Novo Nordisk.
When to get help
| Sign | Who to contact | How fast | Source |
|---|---|---|---|
| Confusion, fainting, no urine, or a very fast heartbeat after vomiting or diarrhoea | Emergency number now | Emergency | MedlinePlus [7] |
| Urine output slowing or stopping, or new swelling of the legs, ankles or feet | Your provider the same day | Today | MedlinePlus [6] |
| Nausea, vomiting or diarrhoea that does not go away | Your prescriber straight away | Today | Medication Guide [1] |
| Metallic taste, easy bruising or reduced urine on Saxenda® | Your prescriber the same day | Today | EU leaflet [2]; MedlinePlus [6] |
| Existing kidney disease before starting Saxenda® | Tell your prescriber before you start | At your next appointment | Canadian leaflet [3]; EU SmPC [2] |
