I don't know the answer, but I have read the augmentation studies on the NIH website and this isn't the way to do them. If you take a medication and it doesn't work, as you say, you don't add another med to it, you find another med that works. You only add to a med that's working but not well enough. Do you have a psychiatrist or a regular doc doing this? Also, is anxiety your main problem or is it caused by depression? I ask because if anxiety is the main problem wellbutrin wouldn't be a drug to use, as it's the most stimulating antidepressant out there short of taking speed. There may be good reasons for what's happening here, but I'd want more info if I were you. As for your main question, I'd check the website of the manufacturer and some of the better more reliable sites such as Mayo Clinic and NIH. Asking a pharmacist is also a good idea about contraindications and how often bad reactions might be happening.
Took those together to months. Didn't have any breathing problems. Olanzapines sedative effect for me only lasts for maybe 6 or 7 hours. I never felt sedated during the day at all on it. And no benzo seemed to make my breathing worse(unlike when making with certain other mental health meds)