“…In vitro, a number of antibiotics, including P-lactams, macrolides, and quinolones, have been known to be highly active against H. pylori (1,8,10,13,22,30,32,33,36). However, when tested as single agents in clinical studies, erythromycin (23), doxycycline (35), ofloxacin (5), ciprofloxacin (34), and norfloxacin (24) have not succeeded in eradicating H. pylori.…”