LOPERAMIDE

(loe-per'a-mide)

Imodium, Imodium AD, Kaopectate III, Maalox Anti-diarrheal, Pepto Diarrhea Control
Classifications: antidiarrheal;
Therapeutic: antidiarrheal
Pregnancy Category: C

Availability

2 mg tablets, capsules; 1 mg/mL, 1 mg/5 mL liquid

Action

Effective antidiarrheal; synthetic piperidine derivative chemically related to diphenoxylate and to meperidine. Inhibits GI peristaltic activity by direct action on circular and longitudinal intestinal muscles. Prolongs transit time of intestinal contents, increases consistency of stools, and reduces fluid and electrolyte loss.

Therapeutic Effect

Effective as an antidiarrheal agent by prolonging transit time in the colon.

Uses

Acute nonspecific diarrhea, chronic diarrhea associated with inflammatory bowel disease, and to reduce fecal volume from ileostomies.

Contraindications

Conditions in which constipation should be avoided, ileus, severe colitis, bacterial gastroenteritis; acute diarrhea caused by broad-spectrum antibiotics (pseudomembranous colitis) or associated with microorganisms that penetrate intestinal mucosa (e.g., toxigenic Escherichia coli, Salmonella, or Shigella); GI bleeding. Safe use in children <2 y is not established.

Cautious Use

Dehydration; diarrhea caused by invasive bacteria; ulcerative colitis; impaired liver function; prostatic hypertrophy; history of narcotic dependence.

Route & Dosage

Acute Diarrhea
Adult: PO 4 mg followed by 2 mg after each unformed stool (max: 16 mg/d)
Child: PO 2–6 y, 1 mg t.i.d.; 6–8 y, 2 mg b.i.d.; 8–12 y, 2 mg t.i.d.

Chronic Diarrhea
Adult: PO 4 mg followed by 2 mg after each unformed stool until diarrhea is controlled (max: 16 mg/d)
Child: PO 0.1 mg/kg after each unformed stool (usually 1 mg)

Administration

Oral

Do not give prn doses to a child with acute diarrhea.

Adverse Effects (≥1%)

Body as a Whole: Hypersensitivity (skin rash); fever. CNS: Drowsiness, fatigue, dizziness, CNS depression (overdosage). GI: Abdominal discomfort or pain, abdominal distention, bloating, constipation, nausea, vomiting, anorexia, dry mouth; toxic megacolon (patients with ulcerative colitis).

Interactions

Drug: No clinically significant interactions established.

Pharmacokinetics

Absorption: Poorly absorbed from GI tract. Onset: 30–60 min. Peak: 2.5 h solution; 4–5 h capsules. Duration: 4–5 h. Metabolism: In liver. Elimination: Primarily in feces, <2% in urine. Half-Life: 11 h.

Nursing Implications

Assessment & Drug Effects

Monitor therapeutic effectiveness. Chronic diarrhea usually responds within 10 d. If improvement does not occur within this time, it is unlikely that symptoms will be controlled by further administration.
Discontinue if there is no improvement after 48 h of therapy for acute diarrhea.
Monitor fluid and electrolyte balance.
Notify physician promptly if the patient with ulcerative colitis develops abdominal distention or other GI symptoms (possible signs of potentially fatal toxic megacolon).

Patient & Family Education

Notify physician if diarrhea does not stop in a few days or if abdominal pain, distention, or fever develops.
Record number and consistency of stools.
Do not drive or engage in other potentially hazardous activities until response to drug is known.
Do not take alcohol and other CNS depressants concomitantly unless otherwise advised by physician; may enhance drowsiness.
Learn measures to relieve dry mouth; rinse mouth frequently with water, suck hard candy.

Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug

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