Doxycycline Bismuth subsalicylate

Ericsson C D, Feldman S, Pickering L K et al 1982 Influence of subsalicylate bismuth on absorption of doxycycline. Journal of the American Medical Association 247 2266-2267 Ericsson C D, Tannenbaum C, Charles T T 1990 Antisecretory and antiinflammatory properties of bismuth subsalicylate. Reviews of Infectious Diseases 12 (suppi 1) S16-S20... 

H. pylori [269]. Multiple studies investigating azithromycin in combination with one or two other drugs (amoxicillin, metronidazole, tinidazole, tetracycline, bismuth subsalicylate, and/or a PPl) revealed that the more effective azithromycin-containing regimens involved triple therapy [270-275]. In contrast to clarithromycin, azithromycin is not FDA approved for treatment of H. pylori disease. The role of azithromycin in the treatment of H. pylori remains to be defined. Several in vitro and animal studies have suggested that azithromycin may be clinically active in the treatment of early Lyme disease (LD) [276-278], Several clinical trials of treatment of early Lyme disease performed in the United States and Europe comparing azithromycin vs. doxycycline, oral penicillin, amoxicilUn/ probenicid, or oral amoxicillin revealed no significant difference in clinical outcome [279-283]. The precise role and dose of azithromycin in the treatment of early LD remains to be established. 

Bismuth subsalicylate reduces the absorption of tetracycline by 34% and reduces the maximum serum levels of doxycycline by 50%. ° It has been suggested the excipient Veegum (magnesium aluminium silicate) in some bismuth subsalicylate formulations enhances this effect." Bismuth carbonate similarly interacts with the tetracyclines in vitro... 

Ericsson CD, Feldman S, Pickering LK, Cleary TG. Influence of subsalicylate bismuth on absorption of doxycycline. JAMA (1982) 247, 2266-7. 

---