API: Loperamide Hydrochloride

What Is Loperamide Hydrochloride and How Does It Work?

Loperamide hydrochloride is an opiate receptor agonist that decreases the motility of the circular and longitudinal smooth muscles of the intestinal wall. The drug prolongs the transit time of intestinal contents, decreasing loss of water and electrolytes and increasing the viscosity and bulk density of fecal contents. Loperamide hydrochloride also decreases movements of bulk in the colon and suppresses reflexes in the stomach and colon. The drug is used to manage both acute and chronic diarrhea stemming from inflammatory bowel disease, gastroenteritis, or other causes.1

For more information, including a MSDS sheet, please see PNA’s Loperamide page.

Approved Indications

  • Diarrhea: Loperamide hydrochloride is used for the management of and relief from acute nonspecific diarrhea and chronic diarrhea related to inflammatory bowel disease and gastroenteritis. The drug can also be used to reduce the volume of discharge in patients who have undergone an ileostomy, and to control traveler’s diarrhea.

Side Effects and Drug Interactions

Common side effects in patients taking loperamide hydrochloride include2:

  • Dizziness
  • Drowsiness
  • Dry mouth
  • Fatigue
  • Stomach discomfort, pain, or distention
  • Vomiting
  • Constipation
  • Mild skin rash or itching

Patients who suffer from severity of these common side effects should contact their pharmacist or physician right away. Patients who experience a severe allergic reaction (including hives, trouble breathing, or swelling of the face, lips, tongue, or throat), stomach pain or bloating, ongoing, worsening or bloody diarrhea, severe skin reaction (including fever, sore throat, swelling in the face or tongue, burning in the eyes, skin pain, rash, blister and peeling) should inform their physician immediately.3

Patients who are allergic to loperamide hydrochloride should not take this drug. Caution should be used when taking loperamide hydrochloride in conjunction with quinidine or ritonavir, both of which may increase in loperamide plasma levels. Loperamide hydrochloride may reduce the therapeutic efficacy of saquinavir if administered together.

Latest News and Research

Loperamide hydrochloride was developed in 1976 and is currently on the World Health Organization’s (WHO) List of Essential Medicines.4 This list, which is updated every two years, includes drugs that the WHO defines to “satisfy the health care needs of the majority of the population; they should therefore be available at all times in adequate amounts and in appropriate dosage forms, at a price the community can afford.”

While loperamide hydrochloride is well tolerated for treatment of diarrhea in adults, use of the drug in children has been discouraged by experts. In fact, the WHO does not advocate pediatric use of the drug in dire situations, even when diarrhea is life threatening. More recent research shows that while the caution is warranted in children under three years of age, loperamide hydrochloride may be a helpful adjunct to oral rehydration and early refeeding in older pediatric patients.5

This drug is generally not used in pregnant women because of fears of risk and safety. Although one limited study indicated that loperamide hydrochloride might be associated with six major birth defects in a population of 108 patients, a more recent study in a similar population shows that the drug is not associated with the development of major birth malformations.6

Loperamide hydrochloride is also being studied as a possible drug for alleviating opioid withdrawal. Although the drug is not currently approved for this use, a review of user-generated discussion has demonstrated that loperamide hydrochloride is a drug of choice for mediating opioid withdrawal symptoms, with further studies on the subject planned.7

Buying Guide

PNA is a recommended bulk supplier of Loperamide Hydrochloride and other APIs. You can learn more about Loperamide Hydrochloride here.

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Show 7 footnotes

  1. “Loperamide,” September 16, 2013, http://www.drugbank.ca/drugs/DB00836
  2. “Loperamide,” August 1, 2010, https://www.nlm.nih.gov/medlineplus/druginfo/meds/a682280.html
  3. ”Imodium,” 2016, http://www.rxlist.com/imodium-side-effects-drug-center.htm
  4. “WHO Model Lists of Essential Medicines,” August 2015, http://www.who.int/medicines/publications/essentialmedicines/en/
  5. “Loperamide Therapy for Acute Diarrhea in Children: Systematic Review and Meta-Analysis,” March 27, 2007, http://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.0040098
  6. “Prospective, controlled, multicentre study of loperamide in pregnancy,” 2000, http://europepmc.org/abstract/med/10758415
  7. “I Just Wanted to Tell You That Loperamide WILL WORK”: A Web-Based Study of Extra-Medical Use of Loperamide,” June 1, 2013, http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3633632/