Macrolides are a class of antibiotics that includes erythromycin, roxithromycin, clarithromycin and azithromycin. They work by inhibiting bacterial protein synthesis. They are used to treat atypical pneumonia caused by mycoplasma pneumoniae, whooping cough, streptococcal infections and diphtheria and tetanus. Common side effects of erythromycin include epigastric pain, hearing impairment, rashes, hepatitis and jaundice.