<prompt> The drug of choice for the treatment of chlamydial infection is-AmpicillinThird generation cephalosporinsMetronidazoleDoxycycline  <response>: A 7-day course of tetracycline 500 mg four times daily, doxycycline 100 mg twice daily, erythromycin 500 mg four times daily, or a fluoroquinolone ofloxacin, 300 mg twice daily; or levofloxacin, 500 mgd can be used for treatment of uncomplicated chlamydial infections. A single 1-g oral dose of azithromycin is as effective as a 7-day course of doxycycline for the treatment of uncomplicated genital C. trachomatis infections in adults. Harrisons Principles of internal medicine, 20th edition, page 1426 