Final answer:
The best treatment for traveler's diarrhea in this case is ciprofloxacin 500 mg taken twice a day for three days, addressing likely bacterial causes and adhering to CDC guidelines for returning travelers.
Step-by-step explanation:
The medication that is typically prescribed for traveler's diarrhea, particularly when the traveler has returned from areas like the Caribbean, is a fluoroquinolone antibiotic such as ciprofloxacin. This is especially true if a bacterial cause is suspected, and the patient doesn't present signs of severe or dysenteric diarrhea, which may require different management. The Centers for Disease Control and Prevention (CDC) usually recommends that adults take ciprofloxacin 500 mg twice a day (BID) for three days, making option (a) Cipro 500 mg BID for 3 days the best choice for treating traveler's diarrhea in a 44 year old patient without signs of severe disease or contraindications for fluoroquinolones. In cases where diarrhea is mild and not bothersome, treatment may focus on hydration and supportive care rather than antibiotics.
Antidiarrheal agents like Imodium (loperamide) can be used for symptomatic relief but do not address the underlying infection. Erythromycin is not typically the first choice for treatment of traveler's diarrhea, and prolonged antibiotic therapy of 7 days (such as options b and d) is generally not recommended unless specifically indicated. Based on the given case and general clinical guidelines, the shorter duration and effective coverage of option a are recommended.