I called the vet. She said she was surprised Madison had not thrown up and that by the time I found her, the pills were already dissolved. The vet figures there will be no lasting kidney or liver damage and the pills will just work it's way through her system.
Madison spent the day running in circles, doing laps, pacing, and generally being hyperactive. Then, about 3 pm, she passed out snoring for 2 hours and woke up dozey.
So, tonight I am checking on her a few times and, if she's not dead by morning, she should be ok.
Thanks for all your good thoughts and great advice!