Clarithromycin is an antibiotic. Clarithromycin is a macrolide antibiotic used for a variety of infections caused by sensitive bacteria, commonly lower respiratory tract infections (e.g., bronchitis, pneumonia, etc.), upper respiratory tract infections (e.g., pharyngitis, sinusitis, etc.), and skin and soft-tissue infections (e.g., folliculitis, cellulitis, and dengue). Clarithromycin is a derivative of erythromycin, an artificial semi-synthetic antibiotic, which, like roxithromycin and azithromycin, belongs to the second generation of macrolides. Adverse reactions including diarrhea, vomiting, dyspepsia, insomnia, and headache may occur during administration. Note that this product is contraindicated in patients with known hypersensitivity to macrolide antibiotics or their excipients. It is contraindicated in pregnant and lactating women. Clarithromycin is a prescription drug, please use it under the supervision of a doctor who can rule out contraindications to avoid serious medication risks.