Oxybutanin is the generic form of Ditropan. Ditropan now comes in a version that is a "once-a-day" -- I think it's called "Ditropan XL". Detrol is another brand of medicine for this problem.
As I mentioned, I've taken oxybutanin for years. The main side effect is -- particularly when you first start -- a VERY dry mouth, and any other oral cavities you have (like, the vagina, if you're a woman). It can also cause constipation. For the first few weeks, I sucked on (sugar-free) candy or chewed gum, until I adjusted. Now I experience the dry mouth for the first hour or so, and it goes away.
Like any of these meds, some trial-and-error is necessary. I was first prescribed it 3 times a day -- and that was way too much; I wasn't urinating at all. Dropping back to two times a day -- when I first wake up, and right before bedtime, seems to work well.
I have been advised by my dentist to practice careful oral hygiene while on it (since it does dry the mouth and gums, and the dryness can cause all sorts of dental problems.) I brush thoroughly and well, at least twice a day, and use an *alcohol free* mouthwash (like ACT; there are generic forms of it, too.) So far (I've been on oxybutanin for probably nearly 20 years, now) I've not had any increase in dental problems while on it. Most of my dental problems now relate to age -- old fillings cracking, teeth cracking due to age, that sort of thing.
Don't be afraid to talk through this with your doctor. There are several meds for bladder control. Not all of them work well for everyone. Like, when Detrol came out, my doctor wanted me to try it...I had multiple bladder accidents. Then she wanted me to try the DitropanXL -- once a day. Again, problems. So I went back to the generic oxybutanin, and seem to be able to keep the bladder under control. So if one med isn't working well for you, ask about others, and keep working with them -- and with dosages -- until you find something that works for you. There's no guarantee that you'll remain completely dry "forever", but surely you can avoid bathroom runs 20 times a day.
I generally try to urinate once every 3 hours or so. I usually wake just once during the night for a bathroom run, but not always. When I'm out in public..and don't know for certain when/where the next bathroom is!..I'll make use of the bathroom if one is available, but I rarely have the urge that I've "gotta go, RIGHT NOW!!", or worse yet, not being able to control it at all.
...I am not a doctor, nor health professional, and don't pretend to be one, here.....