Definition Analgesic nephropathy refers to kidney damage caused by regular, long-term use of analgesics. Short-term, occasional use of these medications does not seem to cause kidney damage.
What is going on in the body? analgesics may cause kidney damage when a person takes more than 6 to 8 pills every day for several years. This kind of long-term use of pain relievers can occur in people with chronic headaches, back pain, or other pain syndromes.
These medications cause kidney damage in two different ways. The first way is called chronic interstitial nephritis. In this disorder, inflammatory cells cause scarring and result in damaged, shrunken kidneys. The second way is called papillary necrosis. In this case, the inner kidney dies and sloughs off, leaving a damaged kidney. The damage due to these analgesics occurs slowly, over many years. It is usually not diagnosed until severe damage has occurred.
What are the signs and symptoms of the disease? Signs and symptoms of analgesic nephropathy usually come on slowly and may include:
What are the causes and risks of the disease? Long-term, regular use of analgesics such as paracetamol, aspirin, or nonsteroidal anti-inflammatory drugs (NSAIDs) causes this condition. Women are more likely to be affected than men. Those with chronic pain are more likely to use these medications often and over a long enough period of time to cause kidney damage.
What can be done to prevent the disease? A person can prevent this condition by limiting the use of analgesics.
How is the disease diagnosed? Diagnosis starts with a history and physical examination. Kidney function tests will be ordered. A blood test checks the levels of creatinine, blood-urea nitrogen, and electrolytes to help diagnose kidney damage or failure. A urinalysis can also help detect problems with kidney function.
Imaging tests, such as an ultrasound or a CT scan, may be done to check the size of the kidneys and to look for any problems. A biopsy of the kidney may be done as well. This involves inserting a special needle through a person's back and into the kidney. A small piece of the kidney is removed with the needle. This small piece, or biopsy sample, is then sent to the laboratory for examination and testing.
What are the long-term effects of the disease? Kidney function may improve if this condition is caught early and the person stops taking the analgesics. However, kidney failure is often present by the time the diagnosis is made. This type of kidney damage is not usually reversible. A person with kidney failure needs dialysis or a kidney transplant to survive. Dialysis is a procedure to filter the blood. It requires a person to be hooked up to a special blood-filtering machine, sometimes as often as three times a week. This continues for life or until the person gets a kidney transplant.
What are the risks to others? This condition is not contagious and poses no risks to others.
What are the treatments for the disease? A person with analgesic nephropathy is advised to stop using analgesics. If the condition is caught early, this may be the only treatment that is needed. If kidney failure is present, the person will need either Dialysis or a kidney transplant. The person may also need treatment for high blood pressure.
What are the side effects of the treatments? dialysis has many side effects, including infection, salt imbalances, and even death. All surgery carries a risk of bleeding and infection. After a kidney transplant, a person must take powerful medications to prevent the body from rejecting the new kidney. These medications may result in infections and also may damage the new kidney and cause other side effects. Blood pressure medications may cause fatigue, lightheadedness, and erectile dysfunction.
What happens after treatment for the disease? Those with only mild kidney damage who stop using analgesics may be able to lead a normal life. Those with kidney failure usually need treatment for the rest of their lives.
How is the disease monitored? Kidney function is usually monitored with regular blood and urine tests, including kidney function tests, electrolytes, and urinalysis. The symptoms of kidney failure are also monitored.
Author: Rajnish K. Dhingra, MD Reviewer: eknowhow Medical Review Panel Editor: Dr John Hearne Last Updated: 25/04/2005 Contributors Potential conflict of interest information for reviewers available on request
