Medicines are designed to help us. They can lower blood pressure, control pain, fight infections, manage diabetes, reduce inflammation, and treat many other health problems. But the fact that a medicine is commonly used does not mean it is completely risk-free.

Your kidneys play an important role in removing waste products and many medicines from your body. When kidney function is reduced, some medicines can remain in the body longer and may need a lower dose or a different schedule. Some medicines can also contribute directly to kidney injury, particularly when they are taken in high doses, used for long periods, or combined with dehydration or other medications.\Kidney Foundation)

This is why the viral headline “8 pills you shouldn’t take because they will affect your kidneys” needs some clarification.

There isn’t a universal list of eight pills that everyone should avoid. Some of the medicines discussed below are extremely useful and can even protect the kidneys in certain patients. The important issue is how they are used, at what dose, for how long, and whether the person already has kidney disease or other risk factors.

Here are eight important medication groups to know about.

1. Ibuprofen and Other NSAID Painkillers

One of the most important medication groups to understand is NSAIDs, or nonsteroidal anti-inflammatory drugs.

Common examples include:

Ibuprofen
Naproxen
Diclofenac
Indomethacin
Celecoxib
High-dose aspirin

These medicines are widely used for headaches, muscle pain, arthritis, menstrual pain, fever, and other conditions.

The problem is that NSAIDs can reduce blood flow to the kidneys. Regular or high-dose use can increase the risk of kidney damage, particularly in people who already have reduced kidney function. (National Kidney Foundation)

The risk can become greater when someone is dehydrated.

For example, imagine someone has diarrhea or vomiting and becomes dehydrated. They then take a high dose of ibuprofen for pain. The combination can put additional stress on the kidneys.

NIDDK specifically warns that NSAIDs can cause acute kidney injury when taken during dehydration or low blood pressure. (Institut National de Diabète et Digestif)

Does this mean you can never take ibuprofen?

No.

For many people, occasional use as directed may be appropriate.

The concern is particularly with high doses, frequent use, prolonged use, kidney disease, dehydration, and certain medication combinations.

People with chronic kidney disease should discuss NSAID use with their healthcare professional rather than self-treating regularly. (National Kidney Foundation)

2. Naproxen

Naproxen belongs to the same NSAID family as ibuprofen, so it deserves separate attention because it is commonly used for pain and inflammation.

People may take naproxen for:

Back pain
Arthritis
Muscle pain
Headaches
Menstrual pain
Sports injuries

Like other NSAIDs, naproxen can affect blood flow to the kidneys.

The risk is higher when it is taken at high doses or for long periods, particularly in people with chronic kidney disease, high blood pressure, heart disease, or dehydration. (National Kidney Foundation)

One common mistake is assuming that switching from ibuprofen to naproxen automatically eliminates the kidney concern.

It doesn’t.

Both belong to the same general medication family.

If you regularly need pain medication, it is better to discuss the underlying pain and appropriate treatment with a healthcare professional instead of repeatedly increasing or extending NSAID use.

3. Diclofenac

Diclofenac is another NSAID used to treat pain and inflammation.

It may be available as tablets, capsules, injections, gels, or other formulations depending on the country.

Oral diclofenac can affect kidney function, particularly when used at higher doses or for extended periods.

The National Kidney Foundation lists diclofenac among NSAIDs that can contribute to acute kidney injury under certain circumstances.

However, the form of the medicine matters.

A topical preparation applied to the skin generally produces less systemic exposure than oral medication, although it still needs to be used according to the product instructions and individual medical advice.

This is another reason why simply saying “diclofenac is bad for the kidneys” is too simplistic.

The dose, formulation, duration, and patient’s health all matter.

4. Certain Antibiotics

Antibiotics are essential medicines that can save lives by treating bacterial infections.

But some antibiotics can affect kidney function, and many antibiotics are eliminated partly through the kidneys.

When kidney function is reduced, the dose or frequency of certain antibiotics may need to be adjusted.

The National Kidney Foundation explains that many antibiotics leave the body through the kidneys and can build up when kidney function is reduced. Some can also directly contribute to kidney injury.

Examples of antibiotic groups that can require particular attention include certain:

Aminoglycosides
Penicillins
Cephalosporins
Sulfonamides

This does not mean people should avoid antibiotics.

In fact, untreated bacterial infections can themselves become extremely dangerous.

The correct approach is to use the appropriate antibiotic at the appropriate dose.

If someone has chronic kidney disease, they should make sure their doctor or pharmacist knows about their kidney function when an antibiotic is prescribed.

5. Certain Diuretics

Diuretics are often called water pills because they increase the amount of salt and water removed from the body through urine.

They are commonly prescribed for conditions such as:

High blood pressure
Heart failure
Fluid retention
Certain kidney-related conditions

Examples include furosemide and other diuretics.

Here’s where things become complicated.

Diuretics aren’t simply “kidney-damaging pills.”

They can be extremely important treatments and may actually help people who have excessive fluid buildup.

However, excessive fluid loss, dehydration, or inappropriate dosing can create problems for kidney function.

The National Kidney Foundation notes that diuretics can be one factor increasing the risk of acute kidney injury when combined with other factors such as NSAIDs, ACE inhibitors or ARBs, and dehydration.

Therefore, never stop a prescribed diuretic simply because you saw a social-media post saying that water pills are bad for your kidneys.

Your doctor may have prescribed it specifically to protect your heart or control fluid levels.

6. ACE Inhibitors

ACE inhibitors are another medication group that can appear on misleading “kidney-danger” lists.

Examples include medicines whose generic names commonly end in “-pril”, such as:

Lisinopril
Enalapril
Ramipril
Benazepril

These medicines are commonly used for high blood pressure, heart conditions, and certain forms of kidney disease.

Interestingly, ACE inhibitors can actually protect the kidneys in many patients, especially those with certain types of chronic kidney disease and protein in the urine. (National Kidney Foundation)

So why can they appear on lists about kidney injury?

Because they can affect kidney filtration, particularly when someone becomes severely dehydrated or when they are combined with other medications and risk factors.

The National Kidney Foundation explains that ACE inhibitors and ARBs may cause a small decrease in eGFR when treatment begins, but this does not necessarily mean the kidneys are being damaged. Over the long term, these medicines can slow the progression of kidney disease in appropriate patients.

This is an excellent example of why viral medication lists can be misleading.

A medicine can have potential risks while still providing major benefits.

7. ARBs

ARBs, or angiotensin receptor blockers, are another group of blood-pressure medicines.

Common examples include:

Losartan
Valsartan
Irbesartan
Olmesartan

Their generic names commonly end in “-sartan.”

Like ACE inhibitors, ARBs are frequently used to treat high blood pressure and certain kidney conditions.

They can help protect the kidneys in appropriate patients by reducing pressure within the kidney’s filtering structures.

But they also require monitoring in some circumstances.

For example, dehydration and combinations involving NSAIDs and diuretics can increase the risk of acute kidney injury.

This combination is sometimes referred to informally as the “triple whammy” because an ACE inhibitor or ARB, a diuretic, and an NSAID can work together to significantly increase kidney risk under certain conditions.

The solution isn’t to stop these medicines independently.

The solution is to make sure your healthcare professional knows everything you’re taking.

8. Certain Contrast Agents Used During Medical Imaging

The eighth item is slightly different because it isn’t an everyday pill.

Some medical imaging procedures use contrast agents to make structures easier to see.

Certain iodine-based contrast agents used in CT and other imaging procedures can pose kidney risks, particularly in people who already have kidney disease or other risk factors. (National Kidney Foundation)

This does not mean you should refuse a CT scan because of the contrast.

Doctors weigh the benefits of obtaining the necessary medical information against potential risks.

Before an imaging procedure, tell your healthcare team about: