Medicines and the Kidneys: Sorting the Evidence From the Noise
Most avoidable acute kidney injury in the community involves ordinary medicines taken during a dehydrating illness.
Key takeaways
- Dangerous combination: NSAID plus ACE inhibitor or ARB plus diuretic
- Commonly paused when dehydrated: metformin, SGLT2 inhibitors, ACE inhibitors, ARBs, diuretics, NSAIDs
- Most useful single change: Ask for written sick day rules if you take any of these medicines.
- Commonest mistake: Regular over-the-counter NSAIDs if you have kidney disease.
- See a doctor if any of the signs under "When to speak to a doctor" below apply to you.
What it is
How common medicines affect kidney function, and which to pause when unwell. It sits within Kidney Health. Here are the numbers, taken from the guidance cited at the end.
The numbers, in one place
| Measure | Figure |
|---|---|
| Dangerous combination | NSAID plus ACE inhibitor or ARB plus diuretic |
| Commonly paused when dehydrated | metformin, SGLT2 inhibitors, ACE inhibitors, ARBs, diuretics, NSAIDs |
| NSAIDs | reduce kidney blood flow, particularly when dehydrated |
| Contrast scans | may need medicines pausing beforehand |
What helps
These are the changes with the clearest evidence behind them. Start wherever it is easiest to start.
- Ask for written sick day rules if you take any of these medicines
- Pause the listed medicines during vomiting, diarrhoea or high fever, and seek advice
- Use paracetamol rather than NSAIDs for routine pain if you have CKD
- Tell every prescriber about your kidney function
What to avoid
A few of these are widely believed. That is precisely why they are here.
- Regular over-the-counter NSAIDs if you have kidney disease
- Continuing diuretics and ACE inhibitors while significantly dehydrated
- Herbal products, several of which are directly nephrotoxic
Where to go next
- Your Questions About Medicines and the Kidneys, Answered
- The Short Guide to Medicines and the Kidneys
- Medicines and the Kidneys — the reference entry
- The Evidence on Blood in Urine, Without the Hype
- Fluid and Kidney Health: What Published Guidance Supports
When to speak to a doctor
Seek urgent advice if you become dehydrated through vomiting, diarrhoea or fever while taking these medicines, and pause them until you are eating and drinking normally. Seek same-day help for passing much less urine, swelling, confusion or drowsiness, which can indicate acute kidney injury.
Where this comes from
- NICE — Acute kidney injury: prevention, detection and management
- Think Kidneys — sick day guidance
How this page was put together
Every figure, recommendation and warning above is taken from the guidance named in Where this comes from. Nothing on this page is inferred, summarised or generalised beyond what those bodies publish: where they give a number, it is their number, and where they are silent, so are we. Pages are rebuilt whenever the underlying record changes. Sign-off by a named clinician, where it has happened, is shown at the top of the page along with the date.
Medical disclaimer
This article is general information, not medical advice. It cannot account for your own history, medication or circumstances. Always speak to a GP, pharmacist or another qualified health professional before making changes that affect your treatment, and never delay seeking medical advice because of something you have read here. In an emergency, call 999.
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