Anyone taken Visteral?

Just been prescribed Visteral for my pre term contractions. Im already on bed rest and have a 2.5 yr old at home. My hubs is pretty much running the show, and hes kinda struggling but regardless, hes a champ.

Doc says this drug is like a heavy benadryl and will more than likely knock me out entirely. Hes doing whatever he can to get me to 34 wks. (Currently 31)

I cant take Procardia or any other drugs bc of my low bp. So if the Visteral doesnt work, im being admitted and given mag of things dont chill out.

And if that doesnt work, I'll be having a baby.

Doc has assured me Visteral is safe, especially in the 3rd trimester. And I trust him completely.

Has anyone ever taken this drug? What was your experience with it? Did it work?