Analgesic nephropathy results from the longterm ingestion of two antipyretic analgesics (often with caffeine and codeine included), which slowly leads to renal papillary necrosis and interstitial nephritis, and may result in progressive renal failure. This is the result of long-term (typically > 5 years) ingestion of a combination of acetaminophen and aspirin. Removal of these analgesic combinations has been associated with decreased incidence of analgesic nephropathy.
Onset of analgesic nephropathy is insidious, often beginning as increased urine frequency. Bloody urine and flank pain will develop, which may result in obstruction of bladder.
How long have you been on combination of tylenol with other pain medications?