Painkillers and the kidneys

Painkillers are among the most common medicines people buy without a prescription. For someone with healthy kidneys they are usually no problem, but for a kidney patient that is not always so. The message of this article is simple: ask before you take one, and do not stop or change anything on your own.

Why are anti-inflammatory drugs risky?

NKF writes that non-steroidal anti-inflammatory drugs (NSAIDs) reduce blood flow to the kidneys. This can cause sudden kidney injury or make chronic disease worse, especially with heavy or long use. NHS also counts kidney damage among the serious side effects of ibuprofen and lists the signs as shortness of breath, blood in the urine and swelling of the ankles, feet or hands.

NIDDK considers ibuprofen and naproxen harmful for people with kidney disease, diabetes or high blood pressure.

Which medicines are in this group?

NKF counts these as NSAIDs:

• Over the counter: ibuprofen (such as Advil and Motrin), naproxen (such as Aleve) and high-strength aspirin. NKF considers diclofenac gel a lower-risk exception.
• By prescription: celecoxib, diclofenac in any form taken into the body (tablet, capsule, suppository or injection), indomethacin, ketorolac, meloxicam and the higher strengths of ibuprofen and naproxen.

NKF warns to read the label, because the word NSAID appears on some cold remedies too. Check Iranian brand names with your pharmacist.

Who is at higher risk?

NKF says the risk is higher in these people:

• Chronic kidney disease, especially eGFR below 60.
• Liver disease, heart disease, heart failure or high blood pressure.
• People taking blood pressure medicines of the “-pril” or “-sartan” groups, or water tablets (diuretics).
• Heavy or long use.

NHS says ibuprofen may not go well with blood thinners, cortisone-type medicines, antidepressants and blood pressure medicines, so the caution is not only about the kidneys.

Sudden kidney injury

NHS counts long-term use of some medicines, including anti-inflammatory drugs, ACE inhibitors and water tablets, as well as dehydration, among the causes of sudden kidney injury, and says to talk to your doctor before starting any new medicine or supplement. This does not mean stopping them: these blood pressure medicines are needed by many kidney patients. Do not stop them yourself, and ask your doctor what to do with them on days of dehydration, vomiting or diarrhoea. On its kidney infection page, NHS also says not to take ibuprofen unless a doctor says so.

Paracetamol (acetaminophen)

NKF generally considers it safe for the kidneys at a suitable amount, but stresses that you should talk to your doctor before using it and be careful with combination products that may raise your intake without your knowing. NKF reminds us that liver disease can rule it out. The right amount is for your doctor or pharmacist to say.

Other painkillers

• Low-strength aspirin may be prescribed for the heart. NKF says higher strengths act like an NSAID. If you take aspirin for your heart, do not stop it, and ask your doctor.
• Topical gels and ointments such as capsaicin, menthol and lidocaine are not a kidney problem, but too much use raises the blood level of the drug (NKF).
• Opioids (such as tramadol, codeine, morphine) do not directly damage the kidneys, but their breakdown products are cleared by the kidneys and the dose may have to suit the eGFR (NKF). Only on prescription and under a doctor’s supervision.
• Cortisone-type medicines may hold on to water and raise blood pressure and blood sugar. A joint injection usually has fewer side effects than heavy oral courses (NKF).

When you are in pain, what should you do?

Do not leave pain untreated. NKF says untreated pain carries risks too. Do these things:

• Tell your doctor or pharmacist that you have kidney disease, and show your medicine list and eGFR.
• If your doctor has approved a painkiller, use the smallest effective amount for the shortest time.
• Avoid alcohol.
• Ask about non-drug options: physiotherapy, stretching, yoga, massage, acupuncture or tai chi (NKF).
• If you have to take painkillers for a long time, eGFR needs to be checked regularly.

NIDDK also recommends that if you have relied on NSAIDs for chronic pain, you ask about alternatives.

What not to do

• Do not start an anti-inflammatory painkiller without asking.
• Do not stop your blood pressure or diabetes medicine on your own, because of pain or for any other reason.
• Do not take several anti-inflammatory painkillers together.
• Do not take a supplement or herbal tea without asking (NKF).

Warning signs

If after taking an anti-inflammatory your urine has become scant, you have swelling, shortness of breath or blood in the urine, or you have bloody vomit or black, tarry stools (a sign of stomach bleeding, according to NHS), see a doctor right away. In Iran, call 115, Iran’s emergency number. See the full list in the guide “When to get urgent help”.