Loperamide
| Drug monograph · NCLEX study reference | |
| Trade names | Imodium |
|---|---|
| Therapeutic class | Antidiarrheal |
| Pharmacologic class | Opioid receptor agonist (gut-selective) |
| Onset / peak / duration | Onset within 1 hour. |
| Half-life / level | Half-life about 10 hours; no routine level. |
| Routes | PO (oral) |
| High-alert (ISMP) | No |
| Black box warning | None |
| Antidote / reversal | Naloxone for overdose; supportive care. |
| Pregnancy / lactation | Use with caution. |
Nursing pharmacology study reference (NCLEX-style monograph). Numeric values are standard teaching ranges for study and must be verified against current manufacturer labeling before clinical use. This is educational content, not prescribing guidance.
Loperamide (brand name Imodium) — Antidiarrheal; Opioid receptor agonist (gut-selective).
Identification
- Therapeutic class: Antidiarrheal.
- Pharmacologic class: Opioid receptor agonist (gut-selective).
Pharmacology
- Mechanism of action: Slows intestinal motility to reduce diarrhea without central opioid effects at normal doses.
- Onset / peak / duration: Onset within 1 hour.
- Half-life / therapeutic level: Half-life about 10 hours; no routine level.
Clinical use
- Indications: Acute and chronic diarrhea.
- Usual dose, route, frequency: 4 mg PO initially then 2 mg after each loose stool.
- Maximum dose / adjustments: Max 8 mg/day over the counter, 16 mg/day by prescription; do not exceed (cardiac risk with misuse).
Safety
- Contraindications: Bloody diarrhea, suspected infectious or C. difficile diarrhea, ileus.
- Black box warning: None (labeling warns of serious cardiac events with excessive doses).
- Interactions: P-gp and CYP inhibitors raise levels; QT-prolonging drugs with overuse.
- Pregnancy / lactation: Use with caution.
- High-alert: No.
Adverse effects
- Common side effects: Constipation, dizziness, abdominal cramping.
- Serious effects to report: Abdominal distension or ileus, cardiac arrhythmia with high doses.
- Antidote / reversal: Naloxone for overdose; supportive care.
Nursing process
- Assessment before administration: Stool character (rule out blood or infection), hydration.
- Interventions during therapy: Stop if no improvement in 48 hours or if fever or blood appears.
- Monitor: Stool frequency, hydration.
- Evaluation / expected outcome: Reduced diarrhea.
Patient teaching
- Patient teaching: Do not exceed the dose; stay hydrated; stop and seek care for bloody stools or fever.
- Notify provider if: Bloody stools, fever, abdominal swelling, no improvement.
- Administration tips: After each loose stool up to the daily limit.