The short answer is no. Even if your cat is yowling in pain, and you’re tempted to open up your medicine cabinet to see if you have anything to help, it’s best not to. Most human OTC pain meds are toxic to cats, so you should only give your cat human medicine if your vet has approved it. A single dose of OTC medicine could cause liver damage, ulcers, and death. Here are a few common pain relievers toxic to cats that you should avoid: Aspirin: This may cause ulcers, abnormal blood clotting, and damage to the nervous system. Tylenol: It may damage the liver and red blood cells. Ibuprofen and Naproxen: These may cause liver damage, kidney damage, and ulcers.