Olaf said:
The threat of a shot in the bum always works with DS, but it can be all out war. Maybe the shot is going to be what it takes, and does it hurt. Although, if she's like DS, they'll have tie her down.

At this point, I would just quit arguing with her and take her to the doctor. It's time to let her know who's boss and take control back.
Ok, a few things. My older daughter had recurrent strep and we, at one point, had to resort to the shot to knock out the strep. This shot is BRUTAL. Absolutely BRUTAL. It's not in the butt, it's in the muscle of the thigh. You have to use a large bore needle and it takes about 15 seconds to get the very viscous fluid into the leg. My daughter, the nurse and I were all crying by the time it was done because it was so miserable.
We ended up having her tonsils and adenoids removed because of the strep and apnea-related issues. It was the right choice; she's been strep free for a year and no longer has sleeping problems.
Here's the other thing: When I tell my kids to do something, they do it. None of this crap about refusing to do things or throwing pills away. I give them the medicine, they take it. No excuses, no fights, and no arguing. I'm the Mom, and I'm in charge.
It may suck to be them sometimes, but I'm flabbergasted you have to try and sit down in front of a computer to freakin' explain to your child why they don't want to get rheumatic fever and that they need to take their medicine, blah blah blah.
NO.
YOU are the PARENT.
YOU make the decisions.
They don't like it, tough noogies.
You sit that kid down on the chair, hand her the medicine, say "drink it" and stand there and watch her until she does. That's called being a parent. Your kid says no, she sits in that chair until she drinks/eats it, and I don't care if you have to stand there for hours, she doesn't move until she does what you say. That's how it works.
Go ahead and flame me, I don't care, because being a parent isn't about negotiation and placation, it's about raising a healthy kid who has respect for herself and others.