Medicines to Avoid or Use with Care in Kidney Disease
Posted 01 Jul 2026 | Source:

When you have kidney disease, the medicines you take — including some you can buy without a prescription — deserve extra care. The kidneys are responsible for removing many drugs from the body, so reduced kidney function can cause some medicines to accumulate. Other medicines can directly stress or damage the kidneys. This article explains which medications warrant caution, while emphasising that you should never stop a prescribed medicine without medical advice.

Why medications need extra care in kidney disease

There are two main reasons.

• First, many drugs are cleared from the body by the kidneys, so when kidney function is reduced, these drugs can build up to higher-than-intended levels, increasing the risk of side effects. For such drugs, the dose often needs to be reduced.
• Second, some drugs can themselves harm the kidneys, either by reducing blood flow to them or by direct toxic effects. Being aware of both categories helps you and your doctors use medicines safely.

Painkillers: the most important everyday caution

The most important group of medicines to be cautious with are the anti-inflammatory painkillers known as NSAIDs. These include ibuprofen, diclofenac, naproxen, and others, available both on prescription and over the counter, and present in many combination remedies for pain and fever. NSAIDs reduce blood flow to the kidneys and, used regularly or in people with existing kidney disease, can worsen kidney function, sometimes significantly. Occasional use in a person with healthy kidneys is generally low-risk, but regular use, or any use in someone with kidney disease, should be discussed with a doctor. For everyday pain relief, paracetamol is generally a safer choice for the kidneys, though it too should be used at appropriate doses.

Contrast dyes used in scans

Some imaging tests, such as certain CT scans and angiograms, use a contrast dye injected into the bloodstream to improve the images. In people with significantly reduced kidney function, the contrast dye may be associated with a temporary worsening of kidney function. While the contrast is not always the direct cause, people with advanced kidney disease are at higher risk of kidney problems around the time of the scan. This does not mean that contrast-enhanced scans cannot be performed, but your kidney function should be checked beforehand and appropriate precautions taken, such as ensuring adequate hydration. Always inform the healthcare team arranging your scan that you have kidney disease so they can assess the risks and take the necessary precautions.

Certain antibiotics and other prescription drugs

A number of prescription medicines either need dose adjustment in kidney disease or require monitoring. These include certain antibiotics, some antiviral and antifungal drugs, and various others. This does not mean they cannot be used — often they are essential — but the dose may need to be tailored to your kidney function, and sometimes blood levels are monitored. This is routine for doctors who know you have kidney disease, which is why it is so important that every doctor treating you is aware of it.

Herbal remedies, supplements, and traditional medicines

A frequently overlooked source of harm is herbal and traditional remedies, supplements, and over-the-counter tonics. Some of these contain substances that can damage the kidneys or dangerously raise potassium, and because they are perceived as “natural,” people often do not mention them to their doctors. Some traditional preparations have been linked to kidney damage. If you take any such products, it is important to tell your nephrologist, and to be cautious about starting new ones without checking.

Medicines that raise potassium
Some medicines can raise blood potassium, which is already a concern in kidney disease. These include certain blood pressure and heart medications, some of which are also kidney-protective and therefore genuinely beneficial — the point is not to avoid them, but to monitor potassium while taking them. Certain salt substitutes, which replace sodium with potassium, can also raise potassium unexpectedly and are best used only with advice.

The safe approach: communication and review

The single most effective way to use medicines safely in kidney disease is to ensure that everyone treating you knows about your kidney function. Keep an up-to-date list of everything you take, including over-the-counter products, supplements, and traditional remedies, and share it with your doctors and pharmacist. Before starting any new medicine, including one bought without a prescription, it is worth checking whether it is suitable. And crucially, never stop a prescribed medicine on your own because you have read that it affects the kidneys — many such medicines are prescribed precisely because they protect the kidneys, and stopping them can do more harm than good. Always discuss any concerns with your doctor first.

The takeaway

Medication safety in kidney disease comes down to awareness and communication rather than avoidance of all medicines. With your kidney function known to those treating you, doses adjusted where needed, and caution around painkillers and unregulated remedies, medicines can be used safely and effectively.

If you are unsure whether your medications are appropriate for your kidney function, a nephrologist can review them with you. A video consultation is a convenient way to go through your medicine list.