Hey there-- I know this is old, but I thought I would put my two cents in.
I would try double inflating the balloon to help with the spasms. The largest catheter I've seen is called a 'coude cath'--not sure the spelling!! and it has a metal tip (it helps for guys with enlarged prostates) but its secure and has a HUGE balloon, its also red/orange. but that's the biggest, and if you're always going to have a catheter, I wouldn't use the biggest right away.
What I would suggest is wrapping a female menstrual pad around your penis for better absorbtion.. I know that doesn't stop it, but it helps not make a mess/embarassment.
Also, In the hospital I have used what we call O&B suppositories. Its actually opium and belladonna (its restricted substances), and is given rectally. I know they work VERY WELL for people with bladder spasms, but cannot recal why they were having them, it was a while ago. I would look into that though.
Also, are you on any antidepressants? Some may help with bladder issues, as well assist with pain (not sure on spasms, but it may be a shot!)
Have you tried other anti-spasm medications, or for the overactivity of the bladder?
Have you ever flushed your catheter with water/saline? Sometimes having a bit of mucous (you are prone to UTIs with having a perm. catheter) sometimes there is a film that is at the tip, and needs to be pushed asside for it to flow normally, or it may move and gush causing pressure and overflow. Its a suggestion.
How often do you change your catheter? Everywhere is different, but where I work its suggested every 3 months max, and more often if problems are occuring.
I know in the hopsital i've had to 'rig up' devices to help with ostomies that were overactive and always causing a big messy issue--- and we figured it out. I know we use ostomy appliances to cover leaky wounds and the such to keep them from leaking everywhere, and to change things less frequently and cause moisture--that's the important thing, keeping you dry. If you can't feel it, boy do we not want any moisture with pressure near your bum!!
I hope something was figured out though
hope you get some energy back! I have chronic pain and i know how it feels to want to sleep a lot of the day and still have no energy. I started on antidpressants today to help with my neuropathic pain, and of course, secondary help on mood and energy. Here's hoping!!!
Re: Problem with Urinary Catheter, and Bladder-spasms while on amphetamines 
