Loperamide

Class

  • Synthetic piperidine derivative (opioid) antidiarrhoeal

Indications

Administration/Absorption

  • Oral

  • Not significantly absorbed from the gut

Dosage

Distribution

  • Does cross the blood-brain barrier

    • However it is immediately pumped back out into non–central nervous system (CNS) circulation by P-glycoprotein

    • This mechanism effectively shields the CNS from exposure (and thus risk of CNS addiction) to loperamide

  • NB many drugs are known to inhibit P-glycoprotein and may thus render the CNS vulnerable to opiate agonism by loperamide

Mechanism

Excretion

  • Unchanged in faeces

  • Half life 9.1 to 14.4 hours (average 10.8 hours)

Side effects

  • Abdominal pain and bloating, nausea, vomiting and constipation

Interactions

Contraindications