methotextrate. Since I have started taking this medication my cat has started biting me (breaking skin) to the point of being infected 3x. Have any of you experienced this? My cat was a total lover until I started taking this medication; he doesn't bite anyone else. husband was about to "trade" Sam in at the animal shelter for another cat because of the level of infection & the number of times he's bitten me. (by the way, I've taken Sam to the vet & he's healthy & has seen things like this before.) Any ideas, suggestions would be helpful.