I did a search, and here are some threads which may be helpful in some way (I hope I've pasted these right--if the links don't work, just do a search on the key words of interest):http://www.mothering.com/discussions...ghlight=zofranhttp://www.mothering.com/discussions...ghlight=zofranhttp://www.mothering.com/discussions...ghlight=zofranhttp://www.mothering.com/discussions...ghlight=zofran
I also highly recommend helpher.org (it's *all* about hyperemesis in pregnancy). There is all sorts of info there, and discussion groups, so you can ask anything you want about these medications there and hear all sorts of responses.
I think the rec on meds is that they should be considered if you've lost a certain amount of weight and/or you get dehydrated (there's a good run-down on that at helpher.org). Obviously, if non-medication strategies work, they should be used first. I started on Zofran after non-stop all night barfing landed me in the ER on an IV. I also (independently) had lost several pounds (~8 by ob's scale, ~10 by home scale) by ~7-8 wks.
My personal experience with Zofran is that it is very effective in stopping the barfing, but it does very little for my nausea. It also gives me absolutely intractible constipation (not an uncommon side effect). I tried Phenergan, but it upsets my stomach (kind of funny in a twisted way) and didn't help the barfing/nausea at all. I'm now on Reglan, which seems to be the most effective overall (but it makes me a little bit sleepy). Zofran is available in sublingual tabs (no swallowing!), and I think you can get the other 2 as suppositories, but I have a 2ndary condition which counter-indicates that. Zofran is the newest of the 3, is not available in a generic form, and is very expensive and not covered by all insurance (I was lucky--mine covered it, though the co-pay amounted to $3/tab).
I hope this helps. It seems like there have been many threads in the last month or 2 about morning sickness, hyperemesis, and these medications. Maybe it's time to start a sticky about M/S and HG.