Erythromycin is produced by a strain of Streptomyces Erythraeus and belongs to the macrolide group of antibiotics. It is basic and readily forms salts with acids. The base, the stearate salt and the esters are poorly soluble in water. Erythromycin ethylsuccinate is an ester of erythromycin suitable for oral administration.

Erythromycin may be considered as the prototype of antibiotics as it has the effect of preventing protein synthesis at bacterial ribosomes, resulting in the death of the organism.

Erythromycin appears to inhibit protein synthesis in susceptible organisms by reversibly binding to ribosomal subunits, thereby inhibiting translocation of aminoacyl transfer-RNA and inhibiting polypeptide synthesis.

Erythromycin may be used for the treatment of the pneumonias such as legionella pneumonia and Pneumococcal pneumonia and provides a good alternative to the tetracyclines for chlamydial infections and mycoplasms. However, haemopilus influenzae are usually resistant. It may also be used for the treatment of streptococcal pharyngitis, skin infections (eryspela, impetigo) and erythrasma.

Erythromycin has a similar effect as tetracyclines against acne; it can be used both systemically (by mouth) and topically (applied direct to affected area). It is also known to be effective against chlamydial infections in the genito-urinary tract and eyes (conjuctivitus).

Formal Chemical Name (IUPAC)