My new cat has diarrhea & vomiting after adoption meds. See vet?

Congrats on your new cat, but I'm sorry Hana isn't doing well! It is concerning that she is experiencing both vomiting and diarrhea, and it could be caused by a change in diet, intestinal worms, a GI illness, or a foreign body among other things. The Drontal can also cause some GI upset as well. I do think it's a good idea that Hana is seen by a vet since she is experiencing both vomiting and diarrhea, and I would see if your vet can see her tomorrow along with your other cat. Hold off on the cat probiotics for now since she is vomiting, and talk to the vet to see if they feel they will be helpful to her. I would withhold food for tonight, she can have water, and then give her some boiled white meat chicken (no bones) in small amounts in the morning to see if she can keep that down. Good luck, I hope this helps!