Possibly.. BUT you need to consult with a vet about dosages... do not use a human dose on a cat without first talking to a vet. Cats are VERY sensitive to medications and you should never give a cat any medication with out veterinarian supervision
The erythromycin medication cannot work for the cat with infected abscess. This medication is suited for people allergy to penicillin's. You are required to take the cat to a vet for the appropriate treatment.