The present invention is directed to a pharmaceutical composition comprising a therapeutically effective amount of misoprostol and an effective amount of an antibiotic. A suitable antibiotic is selected from the group consisting of doxycycline, gentamicin, tobramicin, ciprofloxacin, clindamycin, clarithromycin, azithromycin and metronidazole. Preferred antibiotics are doxycycline and ciprofloxacin. More preferably, the antibiotic is doxycycline. In its second aspect, the present invention is directed to a method for treating periodontal disease in a mammalian patient comprising administering to a mammalian patient in need of such treatment a therapeutically effective amount of misoprostol and an effective amount of an antibiotic. Typically, the mammalian patient is a human.