Yes. This is a high dose. Your doctor may explain why this is necessary in your case.
Yes. But not unreasonable under certain circumstances. I would consider 40 mg a seriously large dose. That would be roughly equivalent to 80 mg of Prozac and 80 mg of Celexa and possibly to 200 mg of zoloft. Paxil (paroxetine) at 80 mg would be a seriously large dose as well. Most often individual responses determine what is a seriously large dose of medication. All metabolisms are different.