I'm not sure, but Meep is absolutely fanatical about eating grass.  As
soon as we let her outside, she's grazing (well, after the 5 or 10
seconds of concrete-rolling).   The results are predictable:  She eats
grass, vomits grass and bile, then a few moments later, vomits again,
a smaller amount of usually just bile.  We've learned to ensure she
can't get inside for a bit after letting her out, because she'd much
rather ralf on our carpet than on the grass or concrete outside.

I've asked the vet about this, she just told me some cats are
obsessed, and in Meep's case, it's nothing to worry about.  

But in your case, since she's vomiting up her medicine probably, I'd
definitely talk to your vet.

jmc
usenet [at] jodi [dit] ws
Any day you learn something isn't a total waste.

Cats eat grass as a purgative. Probably your cat is not sick. But if you don't
like the cat vomiting grass, you can keep the cat indoors.

www.mimiforsyth.com