Dos & Don'ts
- Use probiotics during and after antibiotics to prevent potential side effects Taking Saccharomyces, Lactobacillus, and Bifidobacterium may prevent diarrhea and yeast infections from developing after antibiotic therapy.
Ask your doctor whether vitamin K might help you to side-step possible side effects
Though it isn’t known whether levofloxacin reduces vitamin K levels in the liver and colon, some antibiotics do, so discuss with your doctor whether adding a supplement makes sense for you.
- Take magnesium, iron, and zinc at the same time as this drug Magnesium can prevent the drug from being absorbed by the intestine, and therefore make it less effective. Supplements or antacids containing these minerals, if used, should be taken two hours before or after taking levofloxacin.
Summary of Interactions with Vitamins, Herbs, & Foods
|May Be Beneficial: Depletion or interference—This medication may deplete these substances from the body or interfere with how they work; extra intake may help replenish them.||
|May Be Beneficial: Side effect reduction and/or prevention—These substances may help reduce the likelihood and/or severity of a potential side effect caused by the medication.||
|May Be Beneficial: Supportive interaction—These substances may help this medication work better.||
|Avoid: Reduces drug effectiveness—When taking this medication, avoid these substances as they may decrease the medication's absorption and/or activity in the body.||
|Avoid: Adverse interaction—When taking this medication, avoid these substances, as the combination may cause undesirable or dangerous interactions.||
|Check: Explanation needed—When taking this medication, read the article details and discuss them with your doctor or pharmacist before taking these substances.||
Interactions with Vitamins
Taking magnesium supplements at the same time as levofloxacin can reduce the intestinal absorption—and thus the effectiveness—of the drug.1 Consequently, nutritional supplements or antacids containing magnesium, if used, should be taken two hours before or after taking levofloxacin.
Taking iron supplements concomitantly with levofloxacin can reduce the absorption—and thus the effectiveness—of the drug.2 Therefore, nutritional supplements containing iron, if used, should be taken two hours before or after taking levofloxacin.
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 boulardii 4 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
Several cases of excessive bleeding have been reported in people who take antibiotics.8 , 9 , 10 , 11 This side effect may be the result of reduced vitamin K activity and/or reduced vitamin K production by bacteria in the colon. One study showed that people who had taken broad-spectrum antibiotics had lower liver concentrations of vitamin K2 (menaquinone), though vitamin K1 (phylloquinone) levels remained normal.12 Several antibiotics appear to exert a strong effect on vitamin K activity, while others may not have any effect. Therefore, one should refer to a specific antibiotic for information on whether it interacts with vitamin K. Doctors of natural medicine sometimes recommend vitamin K supplementation to people taking antibiotics. Additional research is needed to determine whether the amount of vitamin K1 found in some multivitamins is sufficient to prevent antibiotic-induced bleeding. Moreover, most multivitamins do not contain vitamin K.
Interactions with Foods & Other Compounds
Caffeine may have an intensified effect in people taking levofloxacin. Drugs similar to levofloxacin have been shown to cause caffeine to persist longer in the blood.13 However, the effects of levofloxacin on caffeine blood levels or symptoms of caffeine ingestion have not been studied.
1. Fish DN, Chow AT. The clinical pharmacokinetics of levofloxacin. Clin Pharmacokinet 1997;32:101–19.
2. Fish DN, Chow AT. The clinical pharmacokinetics of levofloxacin. Clin Pharmacokinet 1997;32:101–19.
3. Elmer GW, Surawicz CM, McFarland LV. Biotherapeutic agents. A neglected modality for the treatment and prevention of selected intestinal and vaginal infections. JAMA 1996;275:870–6 [review].
4. Elmer GW, Surawicz CM, McFarland LV. Biotherapeutic agents. A neglected modality for the treatment and prevention of selected intestinal and vaginal infections. JAMA 1996;275:870–6 [review].
5. Schellenberg D, Bonington A, Champion CM, et al. Treatment of Clostridium difficile diarrhoea with brewer’s yeast. Lancet 1994;343:171–2.
6. Surawicz CM, Elmer GW, Speelman P, et al. Prevention of antibiotic-associated diarrhea by Saccharomyces boulardii: A prospective study. Gastroenterol 1989;96:981–8.
7. Elmer GW, Surawicz CM, McFarland LV. Biotherapeutic agents. A neglected modality for the treatment and prevention of selected intestinal and vaginal infections. JAMA 1996;275:870–6 [review].
8. Suzuki K, Fukushima T, Meguro K, et al. Intracranial hemorrhage in an infant owing to vitamin K deficiency despite prophylaxis. Childs Nerv Syst 1999;15:292–4.
9. Huilgol VR, Markus SL, Vakil NB. Antibiotic-induced iatrogenic hemobilia. Am J Gastroenterol 1997;92:706–7.
10. Bandrowsky T, Vorono AA, Borris TJ, Marcantoni HW. Amoxicllin-related postextraction bleeding in an anticoagulated patient with tranexamic acid rinses. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1996;82:610–2.
11. Kaiser CW, McAuliffe JD, Barth RJ, Lynch JA. Hypoprothrombinemia and hemorrhage in a surgical patient treated with cefotetan. Arch Surg 1991;126:524–5.
12. Conly J, Stein K. Reduction of vitamin K2 concentration in human liver associated with the use of broad spectrum antimicrobials. Clin Invest Med 1994;17:531–9.
13. Barnett G, Segura J, de la Torre R, Carbo M. Pharmacokinetic determination of relative potency of quinolone inhibition of caffeine disposition. Eur J Clin Pharmacol 1990;39:63–9.
Last Review: 08-17-2011
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