1. Department of Internal medicine, Dutch national center of expertise for retroperitoneal fibrosis Albert Schweitzer hospital Dordrecht The Netherlands
2. Department of Clinical Pharmacy & Toxicology Leiden University Medical Center Leiden The Netherlands
3. Netherlands Pharmacovigilance Centre Lareb 's‐Hertogenbosch The Netherlands
4. Department of Pharmacotherapy, epidemiology and economics, Groningen Research Institute of Pharmacy University of Groningen The Netherlands