(Hyperhidrosis started all of a sudden last year when I was 14 years old and I don't know why it started randomly) I'm a 15 year old girl with a clean bill of health and been taking oxybutynin for 6 months and it was working fine. All of a sudden it stopped working for me. The doctor switched me to Ditropan XL for a higher dosage (30mg/day) but that didn't work either. Then tried taking the ER and the XL together (4)XL 5mg tabs in morning then (1) 5mg ER tab shortly after that worked for only a couple days but then started sweating again. Please help It's affecting my life!