Erythromycin ethylsuccinate- 13 C,d 3 is the 13 C- and deuterium labeled Erythromycin Ethylsuccinate. Erythromycin Ethylsuccinate is an antibiotic useful for the treatment of a number of bacterial infections, has an antimicrobial spectrum similar to or slightly wider than that of penicillin. Erythromycin Ethylsuccinate has antiviral activity against HIV-1.