Which antibiotic is prescribed to treat bronchitis?

Depends: Acute bronchitis is seldom due to bacterial infection and antibiotics are not only unnecessary, but contraindicated. For acute exacerbations of chronic bronchitis (most often a result of smoking), use of agents which are effective against normal upper respiratory tract flora (hemophilus, streptococci, etc.) is advised. Doxycycline is one of several which are often prescribed.