Loperamide

Snapshot

• A 19-year-old man travels to Southeast Asia for a backpacking trip. He had never traveled outside the United States before this. He is excited about all the street food and spends the first night wandering night markets and eating local snacks from street stalls. The next morning, he develops watery diarrhea and a low-grade fever. He continues to have episodes of diarrhea throughout the day. He is able to drink water and eat crackers. On e-consultation with his primary care doctor’s office, where tele-travel medicine is available, he is instructed to take loperamide and hydrate with oral electrolyte solution if available.

Introduction

• Drugs
  • loperamide
• Mechanism of action   
  • μ-opioid receptor agonist, which decreases gut motility
    • decreases fecal volume
    • increase viscosity in the gut
  • because it has poor central nervous systemic penetration, there is low concern for addiction
• Clinical use
  • diarrhea
• Adverse effects 
  • constipation
  • nausea
  • dry mouth
  • can have QT prolongation