Paracetamol, packaged under the trade names of Panadol, Panadeine, Dymadon, Panamax, and many others, is highly toxic to cats. Never administer paracetamol or any other pain-killer to your cat without direct advice from your vet.
Cats metabolise paracetamol differently to dogs and humans. The cat's liver breaks paracetamol down to a toxic chemical which damages the liver and reduces the ability of red blood cells to carry oxygen around the body.
The signs of paracetamol toxicity in cats include brownish gums, difficult breathing and a fast heart rate. Many become very flat and develop swelling of the paws and face. Without treatment they vomit and pass dark brown urine, and their skin may change colour to yellow(jaundice). Cats dosed with paracetamol die if they are not taken to the vet and treated within an hour or so.
Aspirin is equally dangerous but more subtle in its effects. Aspirin damages cats’ kidneys and irritates their stomachs.
Very few pain medications are safe for cats. Only give medications prescribed by your vet for your particular puss.