Azithromycin works through a sophisticated mechanism that makes it uniquely effective against many bacteria, especially those that cause respiratory and atypical infections in children. Unlike antibiotics that destroy bacterial cell walls, azithromycin targets the protein-making machinery inside bacteria. It binds to a specific part of bacterial ribosomes called the 50S subunit, which is like the 'factory' where bacteria make the proteins they need to survive and multiply. By blocking this protein production, azithromycin essentially starves the bacteria of essential proteins, causing them to stop growing and eventually die. What makes azithromycin particularly special is its ability to concentrate in tissues at levels much higher than in the blood - it can reach concentrations in respiratory tissues that are 10-100 times higher than blood levels. This exceptional tissue penetration is why it works so well for lung, sinus, and ear infections. The medication also has a very long half-life, meaning it stays active in the body for days after the last dose is taken. This is why azithromycin courses are typically much shorter (3-5 days) compared to other antibiotics that need to be taken for 7-10 days. The drug continues working for several days after you stop giving it, maintaining therapeutic levels in infected tissues. Azithromycin is particularly effective against 'atypical' bacteria like Mycoplasma pneumoniae and Chlamydia pneumoniae, which are common causes of walking pneumonia in children and don't respond well to traditional antibiotics like amoxicillin. It also works against many typical respiratory bacteria while having excellent activity against some resistant strains that other antibiotics might miss.