Adrienna Jirik, MD
Loperamide is one of the most commonly used medications for symptomatic treatment of acute diarrhea. Its antidiarrheal efficacy lies in several mechanisms: decreasing peristalsis by binding to gut wall opioid receptors, which increases intestinal absorption time; increasing anal sphincter tone; and decreasing intestinal secretion.
When used at minimal effective doses and in the appropriate setting (ie, in nondysenteric type gastrointestinal illnesses), it is overall safe to use and better tolerated than other antimotility medications such diphenoxylate. It has also been found to be more effective in decreasing frequency and duration of diarrhea symptoms when compared with bismuth subsalicylate, another commonly used over-the-counter medication with antisecretory and some anti-inflammatory properties.
Simethicone is an antifoaming medication that decreases the surface tension of bubbles so that gas is more easily expelled. It is used often in combination with the antidiarrheal medications described above. This eases some symptoms of bloating and abdominal discomfort that frequently accompany acute diarrheal illnesses, which alter gut motility and can distend the bowel with more gas and liquid than normal.
Although any of the above medications are fairly easy to obtain individually at the local drugstore in various formulations or dosing schedules, the availability of fixed-dose combination pills (such as the loperamide-simethicone pills mentioned in the article) greatly simplifies treatment regimens for many people and is a welcome therapeutic addition.
Adrienna Jirik, MD
Gastroenterologist
Digestive Disease & Surgery Institute
Cleveland Clinic
Disclosures: Jirik reports no relevant financial disclosures.