Nov. 20, 2018 -- The FDA has approved a new prescription drug for traveler's diarrhea, which affects millions of people a year, cutting short vacations and other trips.
Rifamycin (Aemcolo) is expected to be on the market by mid-February, says Tom Joyce, president and CEO of Aries Pharmaceuticals, the U.S. firm licensed to distribute it here.
The antibacterial drug, taken orally, is approved for the treatment of adults with traveler's diarrhea caused by strains of Escherichia coli (E. coli) that do not involve fever or blood in the stool.
Traveler's diarrhea is the most common travel-related illness, the FDA says, affecting up to 40% of travelers worldwide annually.
The new drug, when available, will mean another agent in the medical arsenal, says Aaron Glatt, MD, chair of medicine and hospital epidemiologist at South Nassau Communities Hospital in Oceanside, NY. But it might not be the best treatment for everyone, as decisions should be made on an individual basis, he says.
Research on Aemcolo
The FDA approved Aemcolo based on studies of effectiveness and safety.
In the effectiveness trial, researchers randomly assigned 264 adults with traveler's diarrhea to the new drug or placebo and found the drug significantly reduced symptoms compared with the placebo.
Two trials looked at safety when the drug was taken over 3 or 4 days by 619 adults. The most common problems with the drug were constipation and headache.
Traveler's diarrhea is defined as having three or more unformed stools in 24 hours in a traveler. Many germs can cause it, but bacteria in contaminated food and water is often to blame. E. coli is a common bacteria, but others can cause it, too.
In the studies, overall, "there was about a 22-hour difference in duration of the symptoms with the drug compared to placebo," Joyce says.
"Aemcolo acts by inhibiting DNA replication and therefore inhibits new bacterial growth," he says.
Among the other treatment options for traveler's diarrhea is a non-fluoroquinolone antibiotic, such as azithromycin. Antibiotics in the fluoroquinolone class, such as ciprofloxacin (Cipro) and others, are options. But the FDA warns that their use can be linked with disabling side effects involving tendons, muscles, joints, nerves, and the central nervous system.
Rifaximin (Xifaxan) was approved by the FDA in 2004. It, too, is not meant for patients whose diarrhea includes fever or blood in the stool.
Costs for the new drug aren't available yet, but Joyce says ''we will be priced at a discount to Xifaxan.” Without insurance, Xifaxan costs about $600 for a 30-day supply, according to online sites. No generic version is available.
Aries is working with insurance companies to develop copay plans, Joyce says.
While the new drug appears to be very safe, Glatt says it is likely to be expensive.
And like other medications for traveler's diarrhea, it should be prescribed on a case-by-case basis.
In general, he says, he shies away from fluoroquinolones, especially ciprofloxacin, due to the concerns about tendon tears and other adverse effects.
Glatt urges travelers to practice prevention to avoid illness in the first place. That means drinking only bottled water in areas where the water may be contaminated, avoiding contaminated food, remembering not to brush teeth with contaminated water, and avoiding ice cubes in areas where the water may not be safe.
Find out the risks at the destination ahead of time, he says, by checking the CDC website.