Josamycin is a macrolide antibiotic belonging to the 16-membered ring group, known for its broad-spectrum activity against many Gram-positive and atypical bacteria. It functions primarily by inhibiting bacterial protein synthesis through binding to the 50S ribosomal subunit. First isolated in the early 1960s from Streptomyces narbonensis, josamycin quickly gained attention as an alternative macrolide with better tolerance and effectiveness against respiratory, skin, and soft-tissue infections, as well as certain intracellular pathogens like Mycoplasma and Chlamydia. Over the decades, it has been widely used in Europe and parts of Asia, especially as an option for patients unable to take erythromycin due to gastrointestinal side effects. Although it is not as universally available as some newer macrolides, josamycin remains clinically relevant for its favorable safety profile, relatively low interaction potential, and its role in treating conditions where resistance to older macrolides has emerged.
