Analgesic abuse, ureteric obstruction, and retroperitoneal fibrosis.

We report two cases of unusual ureteric obstruction in patients with an excessive consumption of analgesics. In a retrospective survey of seven cases of non-malignant retroperitoneal fibrosis seen in the last 15 years it was found that four had taken excessive amounts of analgesics. A careful drug history should be taken in all patients with restroperitoneal fibrosis and ureteric obstruction.