Analgesic nephropathy involves damage to one or both kidneys caused by overexposure to mixtures of medicines, especially over-the-counter pain medicines (analgesics).

Phenacetin nephritis; Nephropathy - analgesic; Nephropathy - NSAID

Analgesic nephropathy involves damage within the internal structures of the kidney. It is caused by long-term use of analgesics (pain medicines), especially over-the-counter (OTC) medicines that contain phenacetin or acetaminophen, and nonsteroidal anti-inflammatory drugs (NSAIDs), such as aspirin or ibuprofen.

This condition frequently occurs as a result of self-medicating, often for some type of chronic pain.

Risk factors include:

• Use of OTC analgesics containing more than one active ingredient
• Taking 6 or more pills a day for 3 years
• Chronic headaches, painful menstrual periods, backache, or musculoskeletal pain
• Emotional or behavioral changes
• History of dependent behaviors including smoking, alcohol use, and excessive use of tranquilizers

There may be no symptoms in the beginning. Over time, as the kidneys are injured by the medicine, symptoms of kidney disease will develop, including:

• Fatigue, weakness
• Increased urinary frequency or urgency
• Blood in the urine
• Flank pain or back pain
• Decreased urine output
• Decreased alertness, including drowsiness, confusion, and lethargy
• Decreased sensation, numbness (especially in the legs)
• Nausea, vomiting
• Easy bruising or bleeding
• Swelling (edema) throughout the body

The primary goals of treatment are to prevent further damage of the kidneys and to treat kidney failure. Your provider may tell you to stop taking all suspect painkillers, particularly OTC medicines.

To treat kidney failure, your provider may suggest diet changes and fluid restriction. Eventually, dialysis or a kidney transplant may be needed.

Counseling may help you develop alternative methods of controlling chronic pain.

The damage to the kidney may be acute and temporary, or chronic and long term.

Complications that may result from analgesic nephropathy include:

• Acute kidney failure
• Chronic kidney failure
• Kidney disorder in which the spaces between the kidney tubules become inflamed (interstitial nephritis)
• Tissue death in areas where the openings of the collecting ducts enter the kidney and where urine flows into the ureters (renal papillary necrosis)
• Urinary tract infections that are ongoing or keep coming back
• High blood pressure
• Cancer of the kidney or ureter

Contact your provider if you have any of the following:

• Symptoms of analgesic nephropathy, especially if you have been using painkillers for a long time
• Blood or solid material in your urine
• Amount of your urine has decreased

Follow your provider's instructions when using medicines, including OTCs. Do not take more than the recommended dose without asking your provider.

Published Date: July 27, 2021
Published By: Walead Latif, MD, Nephrologist and Clinical Associate Professor, Rutgers Medical School, Newark, NJ. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

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