8 Types of Pills You Should Use With Caution Because They Can Harm Your Kidneys

Your kidneys work around the clock to filter waste, balance fluids, and maintain healthy levels of minerals in your blood. But did you know that certain medications can affect how well your kidneys function?

Some commonly used medicines may increase the risk of kidney injury, particularly when taken in high doses, used for long periods, or combined with other medications. The risk can be greater for older adults and people living with diabetes, high blood pressure, dehydration, or existing kidney disease.

This does not mean you should stop taking prescribed medication. Many of these medicines are essential and can be used safely with appropriate medical supervision.

Here are eight medication groups worth discussing with your doctor or pharmacist.

1. Nonsteroidal Anti-Inflammatory Drugs (NSAIDs)

NSAIDs are widely used to relieve pain, inflammation, and fever. Common examples include ibuprofen, naproxen, and diclofenac.

Although effective, these medications can reduce blood flow to the kidneys. Taking them frequently or in high doses may increase the risk of acute kidney injury, especially in people who are dehydrated or already have kidney problems.

What to know: Ask your healthcare professional about safer pain-management options if you have kidney disease or regularly need pain relief.

2. Certain Antibiotics

Some antibiotics can affect the kidneys, particularly when given in high doses or when the dose is not adjusted for reduced kidney function.

Examples include gentamicin and vancomycin, which may require careful monitoring. Certain other antibiotics can also cause kidney-related complications in susceptible individuals.

What to know: Take antibiotics exactly as prescribed. Your healthcare professional may adjust the dose or monitor kidney function when necessary.

3. Proton Pump Inhibitors (PPIs)

Proton pump inhibitors reduce stomach acid and are commonly prescribed for acid reflux, heartburn, and stomach ulcers.

Examples include omeprazole, pantoprazole, and esomeprazole.

In some people, these medications have been associated with acute interstitial nephritis, an inflammatory reaction affecting the kidneys. Long-term use has also been associated with chronic kidney disease in observational studies, although an association does not prove that the medication caused the condition.

What to know: If you take a PPI for a long time, ask your doctor whether you still need it and whether your treatment should be reviewed.

4. Diuretics (Water Pills)

Diuretics help the body eliminate excess salt and water. They are often used to treat high blood pressure, heart failure, and fluid retention.

Examples include furosemide and hydrochlorothiazide.

These medicines can sometimes cause dehydration or changes in electrolyte levels. If too much fluid is lost, blood flow to the kidneys may decrease, potentially leading to kidney injury.

What to know: Follow your prescribed dose and ask your healthcare professional how to manage your medication during vomiting, diarrhea, or other illnesses that cause dehydration.

5. ACE Inhibitors and ARBs

These medications are commonly prescribed to control blood pressure and protect the heart. They can also help slow kidney disease in many patients.

Examples include lisinopril and enalapril (ACE inhibitors), as well as losartan and valsartan (ARBs).

Although these drugs can cause a rise in blood creatinine or contribute to acute kidney injury in certain circumstances, they are often beneficial for kidney health. Risk can increase when someone becomes dehydrated or combines these medicines with NSAIDs and diuretics.

What to know: Your doctor may monitor your kidney function and potassium levels after starting treatment or changing the dose. Do not stop these medications without medical advice.

6. Lithium

Lithium is a medication used to treat certain mental health conditions, including bipolar disorder.

Long-term use can affect the kidneys’ ability to concentrate urine and, in some cases, contribute to chronic kidney damage. Lithium levels can also rise dangerously when kidney function decreases or dehydration occurs.

What to know: People taking lithium generally need regular blood tests and kidney-function monitoring. Contact your prescriber if you experience unusual thirst, excessive urination, or symptoms that may suggest lithium toxicity.

7. Certain Antifungal and Antiviral Medications

Some medicines used to treat fungal and viral infections can affect kidney function.

For example, amphotericin B can cause kidney toxicity, while certain antiviral medications may cause kidney injury or accumulate when kidney function is reduced.

The level of risk depends on the specific medication, dose, treatment duration, hydration status, and the patient’s existing health conditions.

What to know: Tell your healthcare professional if you have kidney disease before starting treatment. Some medicines require dose adjustments or additional monitoring.

8. Certain Immunosuppressant Medications

Immunosuppressants help prevent organ rejection after transplantation and treat some autoimmune diseases.

Examples include cyclosporine and tacrolimus. Both can affect kidney function, particularly when blood levels become too high or treatment requires prolonged use.

However, these medications may be essential to prevent organ rejection or control serious disease.

What to know: Follow your specialist’s instructions and attend scheduled blood tests. Never change your dose or stop treatment on your own.

Who Is Most at Risk of Medication-Related Kidney Damage?

Although kidney injury can occur in anyone, certain factors increase the risk:

• Being an older adult.
• Having chronic kidney disease.
• Living with diabetes or high blood pressure.
• Becoming dehydrated through vomiting, diarrhea, fever, or inadequate fluid intake.
• Taking several medications that affect kidney function.
• Using over-the-counter pain relievers frequently without medical guidance.

The combination of an NSAID, an ACE inhibitor or ARB, and a diuretic can be particularly concerning in susceptible people because these medicines affect kidney blood flow and fluid balance in different ways.

Warning Signs That Should Not Be Ignored

Kidney injury does not always cause noticeable symptoms in its early stages. When symptoms occur, they may include:

• Producing much less urine than usual.
• Swelling in the feet, ankles, or legs.
• Unexplained nausea or vomiting.
• Unusual fatigue or weakness.
• Shortness of breath, particularly when fluid accumulates.

These symptoms can have many causes, but a sudden reduction in urine output, severe breathlessness, or rapidly worsening swelling requires urgent medical assessment.

Blood tests measuring creatinine and estimated glomerular filtration rate (eGFR), along with urine tests when appropriate, can help assess kidney function.

How to Protect Your Kidneys While Taking Medication

You can take several practical steps to reduce avoidable risks:

1. Review your medications regularly. Ask your doctor or pharmacist whether all your prescriptions and over-the-counter products remain appropriate.
2. Avoid unnecessary painkiller use. Frequent NSAID use can be particularly risky if you have kidney disease or become dehydrated.
3. Follow dosing instructions. Some medications need adjustments based on kidney function.
4. Report new symptoms. Tell your healthcare professional about changes in urination, swelling, or unusual weakness.
5. Ask about monitoring. Depending on your medications, regular blood and urine tests may be recommended.
6. Check before using supplements. Herbal products and dietary supplements can contain ingredients that affect the kidneys or interact with medications.

If you are vomiting, experiencing diarrhea, or unable to drink normally, ask your healthcare professional whether any of your medicines need temporary adjustment. Do not independently stop essential prescriptions.

Final Thoughts

Some medications can harm the kidneys, but the risk depends on the medicine, dose, duration of use, and individual health circumstances.

NSAIDs, certain antibiotics, proton pump inhibitors, diuretics, lithium, and some immunosuppressants deserve particular attention in people at increased risk. Other medicines, including ACE inhibitors and ARBs, can actually help protect the kidneys when prescribed appropriately.

The safest approach is not to stop taking your pills out of fear. It is to understand what you take, use each medicine correctly, and review potential risks with a qualified healthcare professional.