Drug Guide
Loperamide Hydrochloride
Classification
Therapeutic: Antidiarrheal
Pharmacological: Opioid receptor agonist
FDA Approved Indications
- Symptomatic relief of acute diarrhea
- Chronic diarrhea associated with inflammatory bowel disease
Mechanism of Action
Loperamide acts on opioid receptors in the myenteric plexus of the intestinal smooth muscle, decreasing intestinal motility and prolonging transit time, which allows for increased absorption of water and electrolytes.
Dosage and Administration
Adult: Initially, 4 mg after the first loose stool, then 2 mg after each subsequent loose stool. Max 16 mg/day.
Pediatric: Not recommended for children under 2 years. For children 2-12 years, dosing should be guided by weight and physician's advice.
Geriatric: Adjust dose cautiously due to potential for increased adverse effects.
Renal Impairment: No specific adjustment required but use cautiously.
Hepatic Impairment: Use with caution; no specific guidelines established.
Pharmacokinetics
Absorption: Well absorbed from the gastrointestinal tract.
Distribution: Widely distributed; crosses the blood-brain barrier minimally under normal conditions.
Metabolism: Metabolized in the liver via CYP3A4 and CYP2C8 enzymes.
Excretion: Excreted mainly in feces; minimal renal excretion.
Half Life: Approximately 10.4 hours.
Contraindications
- Neonates or infants <2 years of age
- Serious infectious diarrhea caused by pathogens like Salmonella, Shigella, Campylobacter, or E. coli
- Hypersensitivity to loperamide
Precautions
- Potential for serious adverse effects like bowel obstruction, toxic megacolon, or ileus in cases of infectious diarrhea. Use cautiously in patients with inflammatory bowel disease, or those at risk of toxic megacolon. Not for use as a treatment for bacterial enterocolitis caused by invasive organisms.
Adverse Reactions - Common
- Constipation (Common)
- Nausea (Common)
- Abdominal pain (Common)
Adverse Reactions - Serious
- Toxic megacolon (Rare)
- Gi ileus or bowel obstruction (Rare)
- Allergic reactions, including rash and hypersensitivity (Rare)
Drug-Drug Interactions
- Clarithromycin, ketoconazole (may increase loperamide levels)
Drug-Food Interactions
N/ADrug-Herb Interactions
N/ANursing Implications
Assessment: Monitor bowel activity, hydration status, and signs of bowel obstruction.
Diagnoses:
- Risk for constipation
- Dehydration
Implementation: Administer as prescribed, advise patients to follow dosing instructions carefully, and avoid use in cases of infectious diarrhea caused by invasive pathogens.
Evaluation: Assess effectiveness in controlling diarrhea and observe for adverse effects.
Patient/Family Teaching
- Do not exceed recommended dose.
- Seek medical attention if symptoms worsen or if signs of serious side effects occur.
- Avoid use in cases of bloody or mucoid diarrhea, or diarrhea caused by invasive organisms.
Special Considerations
Black Box Warnings:
- No black box warnings issued for loperamide at this time.
Genetic Factors: Genetic variations affecting CYP450 enzymes may alter drug metabolism.
Lab Test Interference: None known.
Overdose Management
Signs/Symptoms: Constipation, abdominal distension, or signs of intestinal obstruction; in severe cases, CNS depression or toxic megacolon.
Treatment: Discontinue drug, support hydration, and provide symptomatic treatment. In cases of overdose, activated charcoal may be considered.
Storage and Handling
Storage: Store at room temperature, 20-25°C (68-77°F).
Stability: Stable under recommended storage conditions.