ACE inhibitors and anti-inflammatory painkillers (NSAIDs): kidney and potassium risks

ACE inhibitors include ramipril, lisinopril and enalapril. The NHS says ramipril treats high blood pressure, heart failure and kidney damage. They are usually long-term medicines, often taken for years.

NSAIDs reduce pain and inflammation. Ibuprofen, naproxen and diclofenac are the common ones, and aspirin at pain-relief doses belongs to the same family. They are widely available in shops and pharmacies, which makes it easy to take them without thinking about interactions.

The problem is that both can affect the kidneys, as the sources below describe, and the strain can be greater when they are combined, particularly with other medicines or during dehydration.

The BNF entries for ramipril and lisinopril both state that ibuprofen can increase the risk of nephrotoxicity, meaning harm to the kidneys. They add that both medicines can increase the risk of hyperkalaemia, a high level of potassium in the blood. The same pattern appears for losartan, an angiotensin receptor blocker, where the BNF notes the hyperkalaemia risk with ibuprofen.

The NHS acute kidney injury page lists long-term use of some medicines such as ACE inhibitors, anti-inflammatory medicines and diuretics among the possible causes of acute kidney injury, which it describes as a sudden problem that stops the kidneys working as well as they should and can be very serious for some people.

Many people also take a diuretic. The combination of an ACE inhibitor, a diuretic and an NSAID is sometimes called the triple whammy, and the NHS AKI page names all three groups among medicines whose long-term use can contribute to AKI.

The NHS says anyone can get AKI but it is more common if you are 65 or older, have had AKI before or have recently had surgery. Dehydration, infection, low blood pressure and existing long-term conditions affecting the kidneys, heart or liver also feature among the causes it lists.

The NHS ramipril guidance says to contact your doctor if you get ill with a high temperature, sweating and shaking, vomiting or severe diarrhoea, and that they may advise you to stop ramipril until you feel better and are eating and drinking normally. Adding an NSAID to a day of vomiting and poor fluid intake is the kind of situation prescribers worry about.

Early kidney problems may have no symptoms and are found on blood tests. When symptoms occur, the NHS AKI page lists peeing a lot less than usual, feeling very thirsty, feeling or being sick, swollen feet or legs, feeling tired, dizzy, confused or sleepy, and breathlessness, especially lying down. It advises asking for an urgent GP appointment or getting help from NHS 111.

The NHS ramipril page adds that swollen ankles, blood in your pee or not peeing at all can be signs of kidney problems, and that you should call a doctor or 111 now. High potassium can cause muscle weakness, tiredness, numbness and an irregular heartbeat, as the NHS spironolactone page describes for that medicine. Call 999 for chest pain, collapse or a very irregular or pounding heartbeat with feeling faint.

The NHS ibuprofen page suggests paracetamol as the first thing to try if you can take it, because ibuprofen can cause more side effects. A pharmacist can check paracetamol against your other medicines and recommend a product and dose.

Non-drug approaches such as heat, cold, gentle movement and physiotherapy can help muscle and joint pain. If you have persistent pain, ask your GP to review the cause and the medicine plan rather than relying on repeated over-the-counter NSAIDs. If a doctor decides an NSAID is appropriate, ask what dose, for how long, and whether kidney blood tests should be arranged.

Topical NSAID gels are absorbed less than tablets, but they are still anti-inflammatories, so mention them to a pharmacist when you ask.

The NHS says that to decide the correct ramipril dose your doctor will check your blood pressure and may arrange blood tests to check how well your kidneys are working and the amount of potassium in your blood. These tests are the safety net, and they are worth keeping.

Pharmacists can screen over-the-counter purchases against your regular medicines. In private care the same BNF guidance applies, so the advice is consistent, but sharing your medicines list is the practical step that makes it work.