does this medication act in a fashion similar to baclofen?
Yes, they both act the same, being entirely useless sugar pills. Though both have zero side effects, so true sugar pills.
Zanaflex is a muscle relaxant, just like baclofen is.
It was the top choice of my former pdoc in 2015. This pdoc was a Suboxone doc, used to treating heroin junkies, and he gave me the advice of "Smoke marijuana" when I asked what he would do if he were in my position.
Anyone who wants to try Zanaflex (tizanidine) will surely have no problem getting it since it's not a controlled substance.
IMO, the only muscle relaxant at all likely to help with SA would be Soma. And that's because Soma is metabolized into meprobamate which was a wildly popular tranquilizer sold under the brand name Miltown back in the 1950s. That would be before benzos came along, with Librium in 1960, soon followed by Valium in 1963.
Our beloved DEA made Soma a C-IV controlled substance some years back. It previously was not a controlled substance for decades. Though your body converted it into meprobamate which was a C-IV controlled substance. This means you're not getting it & you can send a Thank You card to the DEA for that. Or you can choose instead to post a sig line similar to mine.