Pharmacy Times – August 2016


Drug Interactions: Insights and Observations


Loperamide: Danger of Elevated Plasma Concentrations


John R. Horn, PharmD, FCCP and Philip D. Hansten, PharmD





1. Regnard C, Twycross R, Mihalyo M et al. Therapeutic reviews: loperamide. J Pain Symptom Manage. 2011;42:319-23.

2. Marraffa JM, Holland MG, Sullivan RW et al. Cardiac conduction disturbance after loperamide abuse. Clin Toxicol. 2014;52:952-7.

3. Enakpene EO, Riaz IB, Shirazi FM et al. The long QT teaser: loperamide abuse. Am J Med. 2015;128:1083-6.

4. Eggleston W, Clark KH and Marraffa JM. Loperamide abuse associated with cardiac dysrhythmia and death. Ann Emerg Med. 2016(April);Epub ahead of print:1-4.

5. Niemi M, Tomio A, Pasanen MK, et al. Itraconazole, gemfibrozil and their combination markedly raise the plasma concentrations of loperamide. Eur J Clin Pharmacol. 2006;62:463-72.

6. Cha Y-J, Lee H, Gu N, et al. Sustained increase in the oral bioavailability of loperamide after a single oral dose of HM30181, a P-glycoprotein inhibitor, in healthy male participants. Basic Clin Pharmacol Toxicol. 2013;113:419-24.

7. Kim TE, Lee H, Lim KS, et al. Effects of HM30181, a P-glycoprotein inhibitor, on the pharmacokinetics and pharmacodynamics of loperamide in healthy volunteers. Br J Clin Pharmacol. 2014;78:556-64.

8. Sadeque AJM, Wandel C, Hauibing H et al. Increased drug delivery to the brain by P-glycoprotein inhibition. Clin Pharmacol Ther. 2000;68:231-7.