Have Cat Questions? Ask a Cat Vet Online.
My name is***** and I am sorry to hear that your cat ate Larstan. This drug is used to control blood pressure in humans. In cats it can cause severe low blood pressure as well as kidney problems. I would strongly recommend taking your cat to the local animal emergency room as soon as possible. They can attempt to induce vomiting and then give activated charcoal to block the absorption of the medication. They will also put him on IV fluids and monitor his blood pressure.
Does this help? What other questions do you have? I can help you find the closest animal ER to you if you feel comfortable sharing your zip code.
Best of luck to you and your kitty,
How is your kitty now? Any problems with the Larstan? Do you have any more questions for me?