disclosed is a pharmaceutical composition for extended release of an erythromycin derivative in the gastrointestinal environment . the composition comprises an erythromycin derivative and a pharmaceutically acceptable polymer so that , when ingested orally , the composition induces statistically significantly lower cmax in the plasma than an immediate release composition of the erythromycin derivative while maintaining bioavailability and minimum concentration substantially equivalent to that of the immediate release composition of the erythromycin derivative upon multiple dosing . the compositions of the invention have an improved taste profile and reduced gastrointestinal side effects as compared to those for the immediate release composition .