Antimotility agent
Antimotility agents are drugs used to alleviate the symptoms of diarrhea. These include loperamide (Imodium), bismuth subsalicylate (Pepto-Bismol),[1] diphenoxylate with atropine (Lomotil), and opiates such as paregoric, tincture of opium, codeine, and morphine. In diarrhea caused by invasive pathogens such as Salmonella, Shigella, and Campylobacter, the use of such agents has generally been strongly discouraged, though evidence is lacking that they are harmful when administered in combination with antibiotics in Clostridium difficile cases.[2] Use of antimotility agents in children and the elderly has also been discouraged in treatment of EHEC (Shiga-like toxin producing Escherichia coli) due to an increased rate of hemolytic uremic syndrome.[3]
Loperamide (Imodium)[edit]
Mechanism of action[edit]
Loperamide is a μ-opioid receptor agonist.[4] By binding to μ-opioid receptors, loperamide inhibits acetylcholine release and decreases excitation of neurons in the myenteric plexus, which leads to a decrease in peristalsis.[4] Decreasing intestinal motility prolongs the transit time of food content through the digestive tract, which allows for more fluid absorption; thereby alleviating diarrhea symptoms and improving stool consistency and frequency.[4]
Unlike other opiates, loperamide does not cross the blood brain barrier, so there is minimal risk for abuse.[5]
Adverse effects[edit]
Side effects of use of anti-motility agents include:
- Constipation[4]
- Abdominal cramps and discomfort[4]
- Nausea[4]
- Drowsiness[6]
- Dizziness[6]
- Dry mouth[6]
- Skin rash[6]
Contraindications[edit]
Contraindications include:
- Severe liver damage[7]
- Children 2 years old or younger[8]
- Malnourished individuals[6]
- Dehydrated individuals[6]
- Bloody diarrhea present[6]
Drug interactions[edit]
CYP3A4 inhibitors, such as erythromycin, fluconazole, ketoconazole, quinidine, and ritonavir, increase plasma levels of loperamide[7]
Bismuth subsalicylate (Pepto-Bismol)[edit]
Mechanism of action[edit]
Bismuth subsalicylate (BSS) has both antibacterial and anti-secretory actions that help with diarrhea.[1] Once in the gut, BSS gets broken down into bismuth and salicylic acid.[1] Bismuth produces other bismuth salts, which blocks the binding and proliferation of bacteria in stomach mucosal cells, leading to a decrease in inflammation in the intestine.[9] Also, BSS inhibits cyclooxygenase enzyme and leads to a decrease in the production of prostaglandins, which are compounds that increase intestinal inflammation and motility.[1] Lastly, this antidiarrheal agent enhances fluid reabsorption, which helps improve diarrhea symptoms and stool consistency.[1]
Adverse effects[edit]
Adverse effects include:
Contraindications[edit]
Contraindications include:
- Pregnancy[8]
- Children with flu-like symptoms[1]
- Allergy to salicylates[8]
- Presence of gastrointestinal ulcers[1]
- Bleeding disorders (ie. hemophilia)[1]
Drug interactions[edit]
Drug interactions may occur with:[1]
- Warfarin
- Probenecid
- Methotrexate
- Medications containing high salicylate content
See also[edit]
References[edit]
- ^ a b c d e f g h i Budisak P, Abbas M (2024). "Bismuth Subsalicylate". StatPearls. Treasure Island (FL): StatPearls Publishing. PMID 32809532. Retrieved 2024-04-22.
- ^ Koo HL, Koo DC, Musher DM, DuPont HL (March 2009). "Antimotility agents for the treatment of Clostridium difficile diarrhea and colitis". Clinical Infectious Diseases. 48 (5): 598–605. doi:10.1086/596711. PMID 19191646.
- ^ Bae WK, Lee YK, Cho MS, Ma SK, Kim SW, Kim NH, et al. (June 2006). "A case of hemolytic uremic syndrome caused by Escherichia coli O104:H4". Yonsei Medical Journal. 47 (3): 437–439. doi:10.3349/ymj.2006.47.3.437. PMC 2688167. PMID 16807997.
- ^ a b c d e f Schiller LR (May 2017). "Antidiarrheal Drug Therapy". Current Gastroenterology Reports. 19 (5): 18. doi:10.1007/s11894-017-0557-x. PMID 28397130.
- ^ Schiller LR, Pardi DS, Sellin JH (February 2017). "Chronic Diarrhea: Diagnosis and Management". Clinical Gastroenterology and Hepatology. 15 (2): 182–193.e3. doi:10.1016/j.cgh.2016.07.028. PMID 27496381.
- ^ a b c d e f g h i j Forrester A (August 1, 2018). "Diarrhea". Retrieved April 27, 2024.
- ^ a b Regnard C, Twycross R, Mihalyo M, Wilcock A (August 2011). "Loperamide". Journal of Pain and Symptom Management. 42 (2): 319–323. doi:10.1016/j.jpainsymman.2011.06.001. PMID 21703817.
- ^ a b c d Leung AK, Leung AA, Wong AH, Hon KL (2019-08-05). "Travelers' Diarrhea: A Clinical Review". Recent Patents on Inflammation & Allergy Drug Discovery. 13 (1): 38–48. doi:10.2174/1872213X13666190514105054. PMC 6751351. PMID 31084597.
- ^ O'Malley PA (March 2020). "Pink Prescribing: Bismuth Subsalicylate; History, Actions, Risks, and Future Use". Clinical Nurse Specialist CNS. 34 (2): 45–47. doi:10.1097/NUR.0000000000000509. PMID 32068631.
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