What exactly is analgesic nephropathy syndrome?

Phenacetin: Analgesic nephropathy is chronic kidney disease caused by long term use of phenacetin, Acetaminophen (tylenol) and certain nsaid's such as ibuprofen. The incidence of this disease is much lower nowadays due to less availability of phenacetin.

Nephropathy syndrome: Analgesic nephropathy syndrome is a term describing damage to the kidney induced by excessive use of analgesic medications such as aspirin, phenacetin, and paracetamol. Any single analgesic medication or combinations of these medications may cause kidney injury.