Roxithromycin is a semi-synthetic macrolide antibiotic. It is used to treat respiratory tract, urinary and soft tissue infections. Roxithromycin is derived from erythromycin, containing the same 14-membered lactone ring. However, an N-oxime side chain is attached to the lactone ring. It is also currently undergoing clinical trials for the treatment of male-pattern hair loss.When taken before a meal, roxithromycin is very rapidly absorbed and diffuses into most tissues and phagocytes. Due to the high concentration in phagocytes, roxithromycin is actively transported to the site of infection. During active phagocytosis, large concentrations of roxithromycin are released.Most common side effects are gastrointestinal diarrhea, nausea, abdominal pain, and vomiting. Less common side effects include central or peripheral nervous system events such as headaches, dizziness, vertigo, and also the rarely seen rashes, abnormal liver function values, and alteration in senses of smell and taste.