Non-steroidal anti-inflammatory drugs (NSAIDS) are common pain medications. They are used to treat fever, body aches and pains, arthritis, headaches, and painful menstruation. Examples of NSAIDS include diclofenac, ibuprofen, and naproxen. Despite their effectiveness, there are safety concerns. Adverse events linked to NSAIDS use are kidney damage, bleeding disturbances, stomach ulcers, and worsening heart conditions.
How do NSAIDS work?
NSAIDS prevent the production of prostaglandin, an important chemical in the body. Injured tissues release prostaglandin which plays a vital role in the onset of inflammation and development of fever and pain. By blocking prostaglandin production, NSAIDS reduce inflammation, fever, and pain.
How do NSAIDS affect the kidneys?
Prostaglandins dilate blood vessels. By dilating blood vessels, prostaglandins increase blood flow to the kidneys where the blood is filtered and returned to circulation.
When you take NSAIDS, it blocks prostaglandin production. The consequence of this is that less blood gets to the kidneys to be filtered. Ultimately, this can cause kidney dysfunction and impaired waste excretion.
In general, people who are young and who take appropriate doses of NSAIDS for a short time are unlikely to have kidney damage. But, if you take high doses of these medications, you can develop acute kidney injury. This kidney injury results from the effect of NSAIDS on the blood vessels of the kidneys or from inducing inflammation in the kidney tissues.
Prolonged use of NSAIDS may result in chronic kidney disease (CKD). Certain factors increase your risk of getting kidney damage when you use NSAIDS. These factors include
- Older age
- Diabetes
- Kidney disease
- Heart disease
- Liver disease
- Certain medications
People over 65 are more prone to the harmful effects of NSAIDS. Similarly, if you already have a condition that affects kidney function, using NSAIDS can lead to kidney damage.
Using NSAIDS with other medications that can harm the kidneys heightens the risk of NSAID-induced kidney injury. Some drugs which increase kidney injury risks are diuretics, angiotensin-converting enzyme inhibitors, and angiotensin receptor blockers.
Patients with CKD from NSAIDS may have protein in their urine. Protein in urine can be damaging to the kidneys. Your doctor would also request serum creatinine which is elevated in CKD. Other consequences of NSAID use include high levels of potassium and acids in the blood.
Can the kidneys recover from NSAID-induced injury?
Thankfully, in most cases, when you stop taking NSAIDS the kidneys recover. When researchers followed up 9 children who developed kidney dysfunction after taking ibuprofen for 1-3 days, they found that kidney function returned to normal within 3-9 days after treating the patient and withdrawing the drug. Another study that looked at patients who took NSAIDS for 6 weeks showed reversibility of kidney damage at 12 weeks of stopping NSAID use.
In a small percentage of individuals, the kidneys do not recover and the patients have persistent kidney damage. For example, when one 2021 study looked at 99 patients who received NSAIDS daily for 12 months, discontinuing therapy did not reverse kidney dysfunction in all the patients.
Which NSAID is least harmful to the kidneys?
All NSAIDS have been linked to kidney damage. However, one study looked at nearly 2 million subjects from 2008 – 2017 and concluded that the lowest risk was with ibuprofen use. The other medications looked at in the study were
- Celcoxib
- Etorcoxib
- Diclofenac
- Piroxicam
- Naproxen
- Indomethacin
- Mefenamic acid
- Sulindec.
Etorcoxib showed the highest risk.
Another study showed that celecoxib had a lower risk. However, this was a smaller study and did not include ibuprofen. NSAIDS used in this study were meloxicam, diclofenac, loxoprofen, and celecoxib.
How to prevent NSAID-induced kidney injury
The best way to prevent NSAID-induced injury is to use them in the lowest possible dose for the shortest possible duration. You should follow your doctor’s prescription and use it only when necessary.
Let your doctor know about any medications you are taking including supplements. Remember that some drugs increase the risk of kidney injury.
Stay hydrated when taking NSAIDS. Avoid situations that cause dehydration like excess alcohol use. If you are ill and have diarrhea or vomiting, you should notify your physician and increase your water intake to match the fluid loss.
If you have a heart, liver, or kidney disease, you should take NSAIDS only under the guidance of your healthcare team.
Alternatives to NSAIDS
There are alternatives to NSAIDS that you can try when you have pain.
Paracetamol is a pain medication that is frequently used in people with kidney disease. Although it has been linked to kidney disease too, it is relatively safer.
If you have severe pain, your doctor may prescribe an opioid medication instead.
There are also natural remedies for pain like a massage, lavender oil, capsaicin ointment, ginger, cloves, and acupuncture.
NSAIDS are common and effective pain medications. They are relatively safe in young individuals who have no underlying medical conditions. People who are older or who have underlying medical conditions like heart, liver or kidney disease should be more cautious.
