Loperamide
Unchecked
Loperamide
Imodium, Imodium A-D
Experience
No personal reports yet
No clinical reports yet
Log in to add your own experience.
Problems
No problems yet. Be the first to suggest one.
+ Add a problemTitration strategies
No titration strategies yet. Be the first to suggest one.
Effects
No effects listed yet. Be the first to suggest one.
Relevant anecdote
No anecdotes yet. Share a relevant one.
Relevant Literature
No literature entries yet.
Log in to submit relevant literature.
Summary
Common uses
Acute non-infectious diarrhea0, IBS with predominant diarrhea0, Chronic diarrhea (selected; cancer, post-cholecystectomy, ostomy)0
Pharmacy
Starting dose
4 mg PO initially, then 2 mg after each loose stool, not to exceed 16 mg/d (8 mg OTC); chronic-use lower
Preparations
2 mg capsules and tablets; 1 mg/5 mL oral solution; combined with simethicone (Imodium Multi-Symptom)
US FDA Max
16 mg/d (8 mg/d OTC)
Pharmacology
Routes
Oral
Onset
30-60 minutes
Duration
8-12 hours
Half-life
~9-14 hours[1]
Bioavailability
~0.3% (oral; extensive first-pass via CYP3A4 and P-glycoprotein-mediated efflux at the intestinal and blood-brain barriers limit systemic and CNS exposure at therapeutic doses)[1]
Pregnancy
Generally considered acceptable when needed.[citation needed]
Legal status
OTC in US
Purported mechanism
Loperamide is a peripherally-acting μ-opioid receptor agonist that slows gut motility and prolongs transit; the absence of CNS analgesia, euphoria, and dependence at therapeutic doses reflects active P-glycoprotein efflux at the blood-brain barrier that keeps CNS concentrations subtherapeutic.0 Cardiotoxicity at high doses (FDA 2016 advisory): supratherapeutic use (sometimes for opioid-substitute euphoria or unintentional megadosing) saturates P-gp, allows systemic accumulation, and produces dose-dependent QT prolongation, torsades, and ventricular arrhythmia. Interactions with CYP3A4/P-gp inhibitors can elevate systemic exposure at standard doses[1].
References
[edit | edit source]- ↑ 1.0 1.1 1.2 FDA Prescribing Information, Imodium (loperamide HCl), Janssen, current revision. https://www.accessdata.fda.gov/drugsatfda_docs/label/2017/017694s056lbl.pdf