I cannot find an exact toxic dose for dogs, there simply isn't enough research, but it appears that because most dogs vomit with ingestion they rid themselves of the drug and thus more serious effects aren't seen.
Possible side effects of ingestion include:
repeated vomiting, nausea and drooling, increased heart rate and blood pressure, and hyperactivity.
Once her vomiting stops to settle her stomach tonight you can give either:
1) Pepcid ac (famotidine) at a dose of one 10mg tablet per 20 to 40 pounds of body weight every 12 hours
2) Prilosec (omeprazole) at 1/2 of a 20mg tablet per 20 to 40 pounds of body weight every 24 hours
These are acid reducers and should help her feel better. They can be given for a few days if necessary.
I also recommend feeding a bland diet of 1/3 boiled, shredded white chicken and 2/3 boiled white rice. You can mix in low salt chicken broth or warm water to make the food softer and easier to eat and swallow.
If she continues to vomit she should see a veterinarian on an emergency basis for intravenous fluids and supportive care.
She should start to eat and feel better as the nausea sensation resolves but we do want to keep a close eye on her as if she continues to vomit he could dehydrate herself.
If you notice a racing or irregular heart rate/rhythm then she should be seen by an emergency clinic for treatment.
You can feel her heart by placing your hand flat on the side of her chest just behind her elbow. Count the number of beats in 15seconds and multiply by 4 to get beats per minute. If her heart rate gets up higher than 170-180 beats per minute consistently she should be seen.
Please let me know if you have any further questions.