DARK Classics in Chemical Neuroscience: Loperamide

Area of Science:

• Pharmacology
• Medicinal Chemistry
• Public Health

Background:

• Loperamide is an FDA-approved, over-the-counter antidiarrheal medication.
• It acts as a potent μ-opioid receptor agonist, generally safe at recommended doses (2-8 mg/day).
• Abuse of loperamide for opioid withdrawal has increased, earning it the nickname "poor man's methadone."

Purpose of the Study:

• To review the synthesis and chemical properties of loperamide.
• To examine the pharmacology and adverse effects of loperamide use.
• To discuss the social implications of loperamide abuse.

Main Methods:

• Literature review of loperamide's chemical properties.
• Analysis of pharmacological data on loperamide's effects.
• Examination of reported cases and public health data on loperamide abuse.

Main Results:

• Loperamide's μ-opioid receptor agonism contributes to its abuse potential.
• High doses lead to central nervous system effects and overdose risks.
• Increased abuse prompted FDA action to limit package sizes in 2018.

Conclusions:

• Loperamide abuse poses significant public health risks.
• Understanding its pharmacology is crucial for addressing misuse.
• Regulatory actions are necessary to mitigate the harms of loperamide abuse.