Ery-Tab is in the drug class macrolide antibiotic and can be used to treat a variety of bacterial infections. This medication might also be used to prevent bacterial infections. Ery-Tab is produced by a strain of Streptomyces erythrasma. This drug works by stopping the growth of bacteria. Ery-Tab, however, cannot be used to treat viral infections such as flu and the common cold since it only treats or prevents bacterial infections.