Your kidneys work quietly around the clock, filtering waste from your blood, balancing fluids and electrolytes, and helping regulate blood pressure.
But there is something many people don’t realize: some medicines that are safe and useful for millions of people can also put additional stress on the kidneys under certain circumstances.
In fact, many of them are important treatments for pain, high blood pressure, infections, heart disease, and other conditions. The key is understanding which medicines deserve extra caution, who is most vulnerable, and when medical advice is important.
Here are eight commonly used medicines and medication groups worth knowing about.
1. Ibuprofen and Other NSAID Painkillers
Nonsteroidal anti-inflammatory drugs, commonly called NSAIDs, are among the most familiar medicines in the home.
Examples include:
- Ibuprofen
- Naproxen
- Diclofenac
- Celecoxib
- Indomethacin
They are used for headaches, arthritis, muscle pain, menstrual pain, fever, and inflammation.
How can they affect the kidneys?
NSAIDs can reduce blood flow to the kidneys. This can become particularly concerning when the kidneys are already vulnerable.
According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), NSAIDs can damage the kidneys when taken for a long time and can contribute to acute kidney injury, particularly when someone is dehydrated or has low blood pressure.
The risk can be greater in people who already have:
- Chronic kidney disease
- High blood pressure
- Diabetes
- Heart disease
- Older age
- Dehydration
Why are NSAIDs still sold?
Because they can be highly effective medicines.
The important issue is appropriate use, not simply whether the medicine is available over the counter.
Taking an NSAID occasionally at the recommended dose may be very different from taking it every day for months.
If you regularly need pain medication, talk with a healthcare professional about whether the medicine and dose are appropriate for you.
2. Certain Antibiotics
Antibiotics can be lifesaving when they are prescribed for bacterial infections.
However, some antibiotics can affect kidney function in susceptible people, and certain antibiotics may require dose adjustments when kidney function is reduced.
The National Kidney Foundation lists certain antibiotics among medications that can contribute to acute kidney injury, particularly when other risk factors are present.
Some drug-related kidney problems occur because of direct effects on kidney tissue, while others may result from allergic or immune reactions.
Does this mean you should avoid antibiotics?
No.
An untreated bacterial infection can itself be dangerous.
The important point is that healthcare professionals should consider kidney function when selecting and dosing certain medicines.
If you have known kidney disease, make sure your doctor and pharmacist know about it before starting a new prescription.
3. ACE Inhibitors
ACE inhibitors include medicines with generic names ending in “-pril,” such as lisinopril and ramipril.
These medications are widely used to treat high blood pressure and certain heart and kidney conditions.
Here’s where things become interesting.
A medicine can affect the kidneys without being “bad for the kidneys.”
ACE inhibitors can cause a change in kidney filtration when treatment begins, but they can also protect kidney function over the long term in appropriate patients, particularly people with certain forms of chronic kidney disease.
The National Kidney Foundation describes ACE inhibitors and ARBs as medicines that can protect the kidneys and heart and reduce pressure within the kidney’s filtering system.
So why the caution?
Problems can occur in certain circumstances, particularly when an ACE inhibitor is combined with dehydration, an NSAID, or certain other medicines.
This is why kidney function and potassium are commonly monitored after starting or changing these medicines.
Never stop an ACE inhibitor simply because you read that it can affect the kidneys. It may have been prescribed specifically because it helps protect your kidneys and cardiovascular system.
4. ARBs
ARBs, or angiotensin receptor blockers, include medicines such as losartan, valsartan, and irbesartan.
Like ACE inhibitors, they are commonly prescribed for high blood pressure and certain kidney and cardiovascular conditions.
They can also be beneficial for people with chronic kidney disease.
However, ARBs can affect kidney filtration and potassium levels, meaning monitoring may be necessary.
The National Kidney Foundation notes that ACE inhibitors and ARBs can protect kidney function while also explaining that certain combinations—including NSAIDs, diuretics, and dehydration—can increase the risk of acute kidney injury.
This illustrates an important lesson:
A medicine’s kidney effects cannot always be judged simply by asking whether it “helps” or “hurts” the kidneys.
The answer can depend on the individual’s health, dose, other medicines, hydration, and reason for treatment.
5. Diuretics or “Water Pills”
Diuretics are medicines that help the body remove excess salt and water through urine.
They are commonly used for:
- High blood pressure
- Heart failure
- Fluid retention
- Certain kidney conditions
Examples include furosemide and other types of diuretics.
Because these medicines alter fluid and electrolyte balance, they can sometimes contribute to problems such as dehydration or abnormal electrolyte levels.
The risk may become more significant when a person is vomiting, has severe diarrhea, cannot drink enough fluids, or is taking several medicines that affect kidney blood flow.
But again, diuretics aren’t inherently harmful.
For many patients, controlling blood pressure and removing excess fluid is an important part of protecting the heart, kidneys, and other organs.
6. Proton Pump Inhibitors
Proton pump inhibitors, often called PPIs, are medicines used to reduce stomach acid.
Examples include:
- Omeprazole
- Pantoprazole
- Lansoprazole
- Esomeprazole
They are commonly prescribed for acid reflux, gastroesophageal reflux disease (GERD), stomach ulcers, and other acid-related conditions.
PPIs have been associated in observational research with certain kidney problems, and kidney-related adverse effects are recognized concerns with these medicines.
That doesn’t mean everyone taking a PPI will develop kidney disease.
The important question is: Do you still need it?
Some people take acid-suppressing medication for a legitimate medical reason. Others may continue taking it longer than originally intended without reviewing whether it is still necessary.
If you have been taking a PPI regularly for a long period, ask your healthcare professional whether you still need it and whether the dose remains appropriate.
Don’t abruptly discontinue a prescription medicine without medical advice.
7. Lithium
Lithium is different from the other medicines on this list because it is not an everyday over-the-counter product.
It is a prescription medicine used for certain psychiatric conditions, and it can be highly effective when appropriately prescribed and monitored.
However, lithium is closely connected to kidney function.
The kidneys remove lithium from the body, and changes in kidney function, fluid balance, or other medications can affect lithium levels.
Long-term lithium treatment can also be associated with kidney problems in some people.
For that reason, people taking lithium generally require appropriate monitoring.
Why is lithium still prescribed?
Because for people who need it, the benefits can be substantial.
The answer isn’t simply to stop lithium because it has kidney considerations. Instead, treatment involves balancing benefits and risks while monitoring kidney function and lithium levels.
Anyone taking lithium should follow their prescriber’s monitoring schedule carefully.
8. Aspirin and Other Salicylate-Containing Medicines
Aspirin deserves a special mention because its effects depend heavily on dose and purpose.
Low-dose aspirin may be prescribed for specific cardiovascular reasons, while higher doses have different effects and risks.
The National Kidney Foundation identifies aspirin above 325 mg per day among NSAID-related risk factors for acute kidney injury, particularly when combined with other vulnerabilities.
That does not mean someone taking prescribed low-dose aspirin should stop taking it.
Aspirin may be an important part of treatment for selected patients.
As with other medicines, the appropriate question is not simply:
“Is aspirin bad for the kidneys?”
Instead, ask:
“Is this dose appropriate for my medical condition and kidney function?”
Why Are These Medicines Still Sold?
This is perhaps the most important question.
If a medicine can affect the kidneys, why isn’t it simply removed from the market?
Because risk and benefit have to be considered together.
A medicine may carry a potential kidney-related risk while providing a significant benefit.
For example:
- An NSAID may provide important relief from severe inflammation and pain.
- An ACE inhibitor may help control blood pressure and slow kidney disease.
- A diuretic may reduce dangerous fluid accumulation.
- An antibiotic may treat a potentially serious infection.
- Lithium may be an essential treatment for someone with a condition for which it has been prescribed.
The fact that a medicine has potential adverse effects does not mean that its benefits disappear.
Instead, safe prescribing involves selecting the right medicine, using an appropriate dose, considering other medications, and monitoring patients when necessary.
The “Triple Whammy” Combination You Should Know
One particularly important medication combination involves:
An ACE inhibitor or ARB + a diuretic + an NSAID.
Each medication may have a legitimate reason for being prescribed.
But when these three factors occur together—particularly during dehydration—the risk of acute kidney injury can increase.
The National Kidney Foundation specifically identifies NSAIDs, ACE inhibitors/ARBs, diuretics, and dehydration as factors that can combine to increase acute kidney injury risk.
This is why it’s important to tell your pharmacist or doctor about every medicine you take, including over-the-counter painkillers.
You may not realize that the pain medicine you purchased yourself could interact with your prescription medications.
Dehydration Can Change the Risk
A medicine that is normally tolerated may become more problematic when you’re severely dehydrated.
For example, vomiting, diarrhea, fever, or simply being unable to drink enough fluids can reduce the amount of blood reaching the kidneys.
NIDDK specifically advises people taking certain blood-pressure medicines to plan ahead for illnesses that cause dehydration and to ask their healthcare professional what they should do with their medications during those situations.
This is particularly important for older adults and people with existing kidney disease.
Who Should Be Extra Careful?
Medication-related kidney problems deserve particular attention if you have:
- Chronic kidney disease
- Diabetes
- High blood pressure
- Heart failure
- A history of acute kidney injury
- Older age
- Frequent dehydration
- Multiple prescription medications
Kidney function can also decline without obvious symptoms, so someone may have reduced kidney function without realizing it.
That is why routine medical monitoring can be important for people taking medicines that affect kidney function.
Warning Signs You Shouldn’t Ignore
Kidney problems do not always cause obvious symptoms early on.
However, seek medical advice promptly if you develop concerning symptoms such as:
- Significant reduction in urination
- New or worsening swelling
- Unusual fatigue or weakness
- Persistent nausea or vomiting
- Confusion
- Shortness of breath
- Sudden changes in blood pressure
- Severe flank or back pain
These symptoms can have many causes, so they do not automatically mean a medicine has damaged your kidneys.
But they deserve appropriate medical evaluation.
How Can You Protect Your Kidneys While Taking Medication?
You don’t need to be afraid of every pill in your medicine cabinet.
Instead, develop a habit of medication awareness.
1. Keep a complete medication list
Include:
- Prescription medicines
- Over-the-counter medicines
- Vitamins
- Herbal products
- Supplements
NIDDK recommends keeping an up-to-date list and sharing it with healthcare professionals.
2. Ask before adding an OTC medicine
A medication sold without a prescription is not necessarily risk-free.
Before regularly taking a painkiller, cold medicine, heartburn medicine, or supplement, ask a pharmacist whether it is appropriate for you.
3. Know your kidney numbers
Depending on your circumstances, your healthcare professional may monitor measures such as serum creatinine and estimated glomerular filtration rate (eGFR).
Urine testing may also be used to look for protein or albumin.
4. Don’t double up ingredients
Some cold and pain products contain several active ingredients.
Taking multiple products without checking the labels can accidentally expose you to more medication than intended.
5. Don’t stop prescription medicines on your own
This is especially important with blood-pressure medicines, heart medicines, psychiatric medicines, and other long-term treatments.
If you’re concerned that a medicine may be affecting your kidneys, contact your healthcare professional rather than simply stopping it.
The Bottom Line
The phrase “kidney-harming medicines” can be misleading.
Some medicines can potentially injure the kidneys, especially at high doses, with prolonged use, during dehydration, or when combined with other medications.
But several medicines on this list can also protect health, control serious diseases, or even help protect kidney function when appropriately prescribed. ACE inhibitors and ARBs are good examples.
The goal isn’t to avoid medication.
The goal is to use medication safely and intelligently.
If you’re an older adult, have kidney disease, take several medicines, or regularly use over-the-counter painkillers, consider asking your doctor or pharmacist:
“Are all of my medicines appropriate for my current kidney function, and do any of them need monitoring or dose adjustment?”
That simple question can be an important step toward safer medication use and better kidney health.