Interactions with Dietary Supplements

Minerals
Minerals including calcium, iron, magnesium, and zinc can bind to fluoroquinolones, including ofloxacin, greatly reducing drug absorption.¹ Ofloxacin should be taken four hours before or two hours after consuming antacids (Maalox®, Mylanta®, Tumms®, Rolaids® and others) that may contain these minerals and mineral-containing supplements.²

Probiotics
A common side effect of antibiotics is diarrhea, which may be caused by the elimination of beneficial bacteria normally found in the colon. Controlled studies have shown that taking probiotic microorganisms—such as Lactobacillus casei, Lactobacillus acidophilus, Bifidobacterium longum, or Saccharomyces boulardii—helps prevent antibiotic-induced diarrhea.³

The diarrhea experienced by some people who take antibiotics also might be due to an overgrowth of the bacterium Clostridium difficile, which causes a disease known as pseudomembranous colitis. Controlled studies have shown that supplementation with harmless yeast—such as Saccharomyces boulardii⁴ or Saccharomyces cerevisiae (baker’s or brewer’s yeast)⁵ —helps prevent recurrence of this infection. In one study, taking 500 mg of Saccharomyces boulardii twice daily enhanced the effectiveness of the antibiotic vancomycin in preventing recurrent clostridium infection.⁶ Therefore, people taking antibiotics who later develop diarrhea might benefit from supplementing with saccharomyces organisms.

Treatment with antibiotics also commonly leads to an overgrowth of yeast (Candida albicans) in the vagina (candida vaginitis) and the intestines (sometimes referred to as “dysbiosis”). Controlled studies have shown that Lactobacillus acidophilus might prevent candida vaginitis.⁷

Vitamin K
Unlike with most other antibiotics, preliminary research suggests that people taking ofloxacin do not need to supplement vitamin K to protect against possible drug-induced depletion.⁸