I take tizanidine daily, and yes, you should be just fine, although avoid if on anything that drops blood pressure sharply, its heavily sedating, but doesn't work on GABA receptors like most sedatives, but as an agonist of the alpha2 adrenoreceptors, lessening catecholamine release.
I find plugged, it is 100% reliable in making me sleep, even during the likes of opiate withdrawal, only snag is its shortish half life.
Usually lasts about 4-5ish hours for me, rectally, 8mg would be enough to knock me out cold, and I have been taking it a while, hell two 2mg tablets will put me out for the count, although I've taken up to about 14-16mg in the past.