My 10 Week Old Puppy Vomited Last Night, Is Shaky

My 10 week old puppy vomited last night, is shaky on his legs, and very lethargic. He may have eaten 1/4 of Comfortus tablet from my older dog. That would be about 205 mg. A tic was taken off of him two weeks ago, which seemed to have only been attached for a day and the vet did not seem concerned about it after she took it off.