Medicine to Prevent Travelers' Diarrhea

Availability, Safety and Effectiveness of Prophylactic Medication

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Since travelers' diarrhea (TD) presents a real health risk to anyone who ventures far from home, it seems logical to wonder if you could prevent travelers' diarrhea by taking some kind of medicine, in addition to observing safe food and drink practices. Seeking an answer to that question, I turned to UpToDate -- a trusted electronic reference used by doctors and patients. Here is the information I found there:

"Prophylactic antibiotics prevent the majority of diarrheal disease in travelers, but cannot be recommended unless the complications of diarrhea or an underlying medical condition make the consequence of dehydration so severe that the benefits of using antibiotic prophylaxis outweigh the risks. Daily antibiotics are expensive and have potential side effects that may exact a medical cost that is unacceptable. The side effects include sun sensitivity, allergic reactions, altered GI flora with colonization by resistant bacteria, yeast infections such as candidal vaginitis, and the risk of C. difficile colitis.

"Some situations in which it might be reasonable to consider prophylactic antibiotics include: known severe inflammatory bowel disease which could be exacerbated by an episode of infectious diarrhea; severe vascular, cardiac, or renal disease that would be seriously compromised by dehydration; or severe immunocompromise such as advanced HIV disease or after a complicated organ transplant such as a liver or cardiac transplant."

A prophylactic medication is one that is used to prevent a disease from developing. This information from UpToDate indicates that antibiotics are a good option only if you suffer from one of the underlying health conditions listed above. For the average traveler, the potential risks of taking an antibiotic seem to outweigh the benefit of using it as a preventative agent.

According to UpToDate, another medication that has been used to prevent travelers' diarrhea is bismuth subsalicylate (found in products such as Pepto-Bismol). The major drawback to this option is that one must take high doses at frequent intervals, which is not only inconvenient, but also places you at risk for the development of salicylate toxicity. (For more on salicylate toxicity, see Sodium Salicylate Overdose).

A third potential option is the use of probiotics, but for now the research on their effectiveness in preventing travelers' diarrhea is mixed.

The Bottom Line

For the average traveler, your best bet in terms of preventing travelers' diarrhea is to be strict about observing safe food and water practices. If, however, you suffer from a serious underlying health problem, it is recommended that you discuss the pros and cons of prophylactic medication with your physician prior to your trip. To end on a promising note, vaccines are currently in the works that may prove to be safe and effective in reducing your risk of travelers' diarrhea. Stay tuned!

Want to learn more about travelers' diarrhea? See UpToDate's topic, "Travelers' Diarrhea" for additional in-depth, current and unbiased medical information, including expert physician recommendations.


Wanke, Christine A. "Travelers' Diarrhea" UpToDate. Accessed: September 2009.