The Daily PANCE and PANRE Fast Track – Question 56 Which of the following is the most effective prophylaxis for traveler's diarrhea? A. Metronidazole B. Ciprofloxacin C. Tetracycline D. Ampicillin Answer B. Options for prophylaxis of traveler's diarrhea include norfloxacin, ciprofloxacin, ofloxacin, or trimethoprim/sulfamethoxazole. RedditShareEmailTweetPinShare