Kidney Disorders- There are many pathological conditions affecting the kidney. These conditions can be caused due to various factors. One of the factors which affect the kidneys is overuse of analgesic medications which can hamper the renal function. In this article, we will discuss about a medical condition called Analgesic Nephropathy which is caused by over consumption of analgesic medications.1 We will discuss various causes, risk factors, symptoms, and treatments for Analgesic nephropathy.
How Is Hereditary Analgesic Nephropathy Defined?
- Analgesic Nephropathy is a medical condition in which there is injury or damage to the kidneys as a result of excessive use of analgesic pain medications.2
- In Analgesic Nephropathy, there is injury/damage to internal structures of kidneys as a result of prolonged use of over the counter analgesic medications like acetaminophen and NSAIDs like ibuprofen.
- If an individual consumes more than six pills a day for approximately four years, then that individual is more prone to develop Analgesic Nephropathy.
- Nephropathy or kidney toxicity is more common in individuals who self medicate or constantly take medications for chronic pain.
- Gender wise, Analgesic Nephropathy usually affects females more than males.
Causes of Analgesic Nephropathy
As stated, the main cause of Analgesic Nephropathy is overuse of analgesic medications, usually more than four pills a day for over 6 years. Now, we will study about how these medications affect the kidney and what is the mechanism.
- Despite well known effects of NSAIDs on kidneys, only very limited evidence is present to prove that there is increased risk of a kidney dysfunction.3
- The damage to the renal structures results in marked thickening of vasa recta capillaries with formation of tubular necrosis and then followed by papillary necrosis with focal as well as segmental glomerulosclerosis and fibrosis.
- There is also associated inflammation surrounding the renal tubules and blood vessels resulting in chronic interstitial nephritis.
- Over consumption of analgesics causes its accumulation of metabolites of analgesics in renal medulla in extremely high concentrations.
- Aspirin also decreases renal blood flow by slowing down prostaglandins.
Risk Factors for Analgesic Nephropathy
Some of the Risk Factors for Consumption of Higher Dosage of Over the Counter Analgesics Are As Follows-
Consumption of Higher Dosage over the Counter Analgesics
- Easy availability of the counter analgesics
- Self medications resulting in consumption of toxic dosage
- Chronic headache
- Musculoskeletal pain
- Emotional or behavioral alterations
- History of smoking
- Alcohol abuse
Diseases Influencing Kidney Toxicity
- Urinary tract infection
- Interstitial nephritis
- Renal stones
- Congestive heart failure
Symptoms of Analgesic Nephropathy
Mild to Moderate Pain-
- Pain mostly localized over flank and is often intermittent and mild.
- Pain becomes continuous and moderate to severe in later stage in few cases.
- In early phase of Analgesic nephropathy, only symptom observed is polyuria and sometimes associated polyuria.
- Polyuria is significant in later stage when kidney is severely damaged.
- During initial phase microscopic hematuria is observed only during microscopic urine examination.
- Later stages urine discoloration may be seen.
- Blood pressure is high in few cases mostly seen in advanced stages.
- Continuous loss of blood in urine may cause anemia.
- As the renal function deteriorates, proteinuria has also been observed.
Diagnosis for Analgesic Nephropathy
In cases of Analgesic Nephropathy, a detailed physical examination may come up with results suggestive of interstitial nephritis or renal failure. In some patients, hypertension is also observed. The physician may also observe abnormal heart tones. Swelling of the lower extremities may also be observed.
Laboratory test results may reveal presence of red or white blood cells in urine in the presence of an infection and even without it. Urine test may also reveal presence of protein in the urine.
Other Tests That May Be Conducted To Confirm The Presence Of Analgesic Nephropathy Are:
- CT scan of kidneys
- Intravenous pyelogram
- Toxicology screening
- Ultrasound of the kidneys.
Treatment for Analgesic Nephropathy
The frontline treatment of Analgesic Nephropathy is to stop all over-the-counter medications. The main goal of treatment is to protect the kidneys from further injury and treat the already present dysfunction which can be done with restricted intake of fluids, dialysis, or even kidney transplant. Counseling may also help in people who are dependent on chronic over-the-counter pain medications to look for other forms of treatment for their pain.
Prognosis of Analgesic Nephropathy
In early phase of Analgesic Nephropathy, the renal function improves with stopping of the offending medications. In advanced cases, the disease may continue to progress.
Some Of The Complications Of Analgesic Nephropathy Are:
- Chronic Kidney Disease
Prevention of Analgesic Nephropathy
Analgesic Nephropathy can definitely be prevented if an individual sticks to limited use of analgesic medications, especially in the elderly population since use of analgesic medications is more in the elderly population and hence they are more prone to Analgesic Nephropathy.
1. Renal damage associated with chronic phenacetin overdosage.
RAPOPORT A, WHITE LW, RANKING GN.
Ann Intern Med. 1962 Dec;57:970-80.
2. Indomethacin reduces glomerular and tubular damage markers but not renal inflammation in chronic kidney disease patients: a post-hoc analysis.
de Borst MH1, Nauta FL, Vogt L, Laverman GD, Gansevoort RT, Navis G.
PLoS One. 2012;7(5):e37957.
3. Hepatic and renal toxicities of indomethacin acid, salt form and complexed forms with hydroxypropyl-β-cyclodextrin on Wistar rats after oral administration.
Ribeiro-Rama AC1, Figueiredo IV, Veiga FJ, Castel-Branco MM, Cabrita AM, Caramona MM.
Fundam Clin Pharmacol. 2011 Oct;25(5):599-607.