Is there a huge difference between the Bupropion SR and the XL?

Hi all. I'm really stressing right now my OB called in a script for (what I thought was) My old Bupropion prescription. But the one I took before was twice daily so it must have been the SR (sustained release) and the one I just filled says XL which I guess is the ER (extended release). I was really adamant yesterday to my doc I was only comfortable taking an antidepressant that I've been on before because I have a 3month old to take care of. She said she was putting in the script and to take it twice a day. So I called her back today to tell her she called in the wrong script and the Secretary was mega rude to me and said it's the same one I was on. BUT ITS NOT. I told her the doc told me not even 24 hours ago that I would be getting the one that's twice daily. And she just ignored me and said it's the right prescription it's just a little "different". I honestly think she was under the impression that I didn't know that Bupropion is the generic of Wellbutrin. I tried calling my primary care doctor so I could find out if this was going to be very different and I had to leave a voicemail. Google isn't too helpful. Can someone ease my nerves and explain the difference? I've been suffering for months putting off taking meds and I finally have the courage to go back on and I'm so confused and uncomfortable now

It's to do with what they surround the molecule with - something that dissolves quickly or slowly. The stuff that dissolves faster means it gets into your bloodstream quicker so can be taken more often a day. The stuff which dissolves more slowly on the ER means you get fewer side effects and only take it once a day. Easiest way is to find a colour copy of the SPC= summary of product characteristics, like this http://db.cbg-meb.nl/mri/spc/nlh-0785-001-002.pdf and compare the two. SR and ER will be different shapes and colours and codes - and if you email the PDF to your practice, they can't argue.

I was confused by this, too.

Apparently (from what I understand), the XL release slower than the SR....that's why you only have to take it once a day as opposed to twice a day.

I do not know of the difference. I take the Co version once a day and haven't had problems. When I first took it a while ago it worked great for 6 months or a year. Then it lost its effectiness and I switched to a few other things but now I take it again.