A lot of the physical side effects are inherent to MAOIs - they have crazy interactions with all kinds of stuff present in most people's bodies. (Hence the psychedelic interactions with DMT that produce the "ayahuasca" effects, and hence the long and hard-to-follow list of things to avoid for 1 or more weeks pre-trip.)

There's a reason why MAO inhibitors are so rarely used in psychiatry. High efficacy, but the side effects are nasty to deal with.