Roxithromycin and clarithromycin have different indications, so it is impossible to compare which of these two drugs is more effective. Roxithromycin is mainly indicated for pharyngitis and tonsillitis caused by Streptococcus pyogenes; pneumonia caused by Mycoplasma pneumoniae or Chlamydia pneumoniae; and urethritis and cervicitis caused by Chlamydia trachomatis. Adverse reactions such as diarrhea, nausea, and vomiting may occur after use. The safety of the drug in children is not clear, pregnant women, lactating women, hepatic insufficiency, and patients should use the drug with caution. This medication should not be used in combination with dihydroergotamine, bromocriptine, terfenadine and other drugs at the same time. People who are allergic to this drug or the ingredients in the formula, erythromycin, are prohibited from using this drug. Clarithromycin is mainly used for the treatment of bronchitis and pneumonia caused by Streptococcus pneumoniae and Legionella pneumophila; skin and soft tissue infections such as folliculitis; Helicobacter pylori infections; and odontogenic infections. Adverse reactions such as abdominal pain, diarrhea, and nausea may occur after using the drug. This medication should not be combined with astemizole, cisapride, pimozide, midazolam, and other medications at the same time. The use of this drug is prohibited for those who are allergic to this drug or the ingredients in the formula, pregnant women, and nursing mothers. The above medicines are for reference only, the exact dosage and usage should follow the doctor’s instructions.