Loperamide

Administration

• Type: Anti-diarrheal, opioid
• Dosage Forms: 1mg, 2mg; 1/5 mL
• Routes of Administration: PO
• Common Trade Names: Imodium, Diamode, Imodium A-D, Imodium A-D EZ Chews, Imodium A-D New Formula, Kao-Paverin, Kaopectate 1-D

Adult Dosing

• Acute Diarrhea:
  • 2mg PO per dose
    • Start: 4mg PO x1, then 2mg PO after each loose stool; Max: 16mg/day

• Chronic Diarrhea
  • 4-8mg/day PO divided qd-tid
    • Start: 4mg PO x1, then 2mg PO after each loose stool until maint. dose established; Max: 16mg/day

Pediatric Dosing

• Acute diarrhea:
  • 2-5 yo, 13-20 kg
    • Dose: 1mg PO x1 after each loose stool
      • Max: 3mg/day
      • Use OTC 1mg/5 sol or 1mg/7.5 mL susp
  • 6-8 yo, 20-30 kg
    • Dose: start 2mg PO x1, then 1mg PO after each loose stool
      • Max: 4mg/day
  • 8-11 yo, 30-40 kg
    • Dose: start 2mg PO x1, then 1mg PO after each loose stool
      • Max: 6mg/day
  • 12 yo and older
    • Dose: start 4mg PO x1, then 2mg PO after each loose stool
      • Max: 8mg/day
• Chronic diarrhea
  • 0.08-0.24mg/kg/day PO divided bid-tid
    • Max: 2mg/dose

Special Populations

• Pregnancy Rating: B
• Lactation risk: Probably safe

Renal Dosing

• Adult:

Hepatic Dosing

• Adult/Pediatric: Reduced first-pass metabolism
  • CNS toxicity

Contraindications

• Allergy to class/drug

If given with:

• potassium acid phosphate
• potassium chloride
• potassium citrate
• potassium phosphate

Adverse Reactions

Serious

• toxic megacolon
• paralytic ileus
• angioedema
• anaphylaxis/anaphylactoid reaction
• toxic epidermal necrolysis
• Stevens-Johnson syndrome
• erythema multiforme
• urinary retention
• heat stroke

Common

• constipation
• nausea
• abdominal cramps
• dizziness

Pharmacology

• Half-life: Half-life: 10.8h
• Metabolism: liver; CYP450: 2C8, 3A4 substrate; Info: P-gp substrate; 40% systemic absorption
• Excretion: feces 30%, urine <2%

Mechanism of Action

binds gut wall opioid receptor, inhibiting peristalsis; increases anal sphinctor tone

References

• Epocrates: Loperamide

Authors

Amr Badawy, Ross Donaldson, Neil Young, Daniel Ostermayer