Azithromycin 500mg is used to treat a wide variety of bacterial infections, including:

• Respiratory tract infections: bronchitis, pneumonia, sinusitis, pharyngitis (strep throat), tonsillitis
• Skin infections: impetigo, cellulitis, erysipelas
• Ear infections: otitis media
• Sexually transmitted diseases: chlamydia, gonorrhea
• Lyme disease
• Other infections: Mycobacterium avium complex (MAC) infection, traveler's diarrhea, pertussis (whooping cough)

Azithromycin is a macrolide antibiotic, which means that it works by stopping the growth of bacteria. It is a broad-spectrum antibiotic, which means that it can be used to treat a wide variety of different infections.

Azithromycin is typically taken once a day for 3-5 days, depending on the type of infection being treated. It is important to take the full course of antibiotics, even if you start to feel better before you finish the medication. This will help to ensure that the infection is completely cured and does not come back.

Azithromycin is generally safe and well-tolerated. However, it can cause some side effects, such as diarrhea, nausea, vomiting, and stomach upset. More serious side effects, such as allergic reactions and liver problems, are rare.

Please note that azithromycin should not be used to treat viral infections, such as the common cold or the flu. Antibiotics are only effective against bacterial infections.