Hello, our 19 year old female cat named Angel recently had a senior panel checkup after her brother Jazzi suddenly became ill and passed away last month. (Seemed sudden, but assuming the issues were developing which we did not catch sooner.) We didn't want another horrible surprise, we took her for a thorough checkup. The Vet said that her test results came out pretty good for 19 year old, no kidney issue like her brother had, but detected a mild case of Hyperthyroid, so he prescribed her Methimazole to take for a few weeks. Since it was found at the early stage, he said he would start her with a small dosage of 2.5 mil twice a day. The medication came with some serious side effects warning and we first got very scared but the vet assured me that he had never seen a cat with a side effect with this medication. She had been taking it for the last 2 weeks and the vet was right, we hadn't seen any side effects and actually it seemed like the med was working since her weight improved and she seemed content and happy. But one day during the 2 weeks, she did not eat and seemed under the weather, but the next day, she was back to herself. Then yesterday, the same thing, she didn't want to eat. She still has a very healthy #2. We noticed that she started to drink water out of her water bowel more often than before in a last few days....which we now know is not a good thing after seeing her brother excessively drinking out of the water bowel towards the end of his time. I am hoping that the medication is not affecting her kidney negatively. Since early this morning, she has been throwing up, first a clear liquid, then orange liquid, and the tiny breakfast she ate this morning – separate times. She is not looking happy. I am wondering if the medication is now starting to give her some side effects since vomiting and lack of appetite are listed among its side effects. I'm not sure if I should stop giving her the med. She actually went to see the Vet on Friday for a monitoring checkup. The result should be in tomorrow. We feel that she is under a good care by our new vet, who is very compassionate. I'm just wondering if anyone can share the experience with Methimazole out there. If anyone has any natural remedy against Hyperthyroid that is working, I would like to hear about it. Thank you very much.