loperamide hydrochloride
Imodium, Imodium A-D, Kaopectate II, Maalox Anti-Diarrheal, Pepto Diarrhea Control

Available forms
Available by prescription only
Capsules: 2 mg
Available without a prescription
Solution: 1 mg/5 ml, 1 mg/ml
Tablets: 2 mg

Indications and dosages
 Acute, nonspecific diarrhea. Adults and children older than age 12: Initially, 4 mg P.O.; then 2 mg after each unformed stool. Maximum dose is 16 mg daily.
Children ages 9 to 11: 2 mg P.O. t.i.d. on first day.
Children ages 6 to 8: 2 mg P.O. b.i.d. on first day.
Children ages 2 to 5: 1 mg P.O. t.i.d. on first day.
 Maintenance dosage is one-third to one-half the initial dose (0.1 mg/kg only after each unformed stool), not to exceed dose recommended on the first day. Discontinue if no improvement after 48 hours.
 Chronic diarrhea. Adults: Initially, 4 mg P.O.; then 2 mg after each unformed stool until diarrhea subsides. Adjust dose to individual response. Discontinue if 16 mg is used for at least 10 days.
Children ◇: 0.08 to 0.24 mg/kg daily in two to three divided doses.
Directions for patient self-medication Adults: 4 teaspoons or 2 tablets P.O. after the first loose bowel movement, followed by 2 teaspoons or 1 tablet after each subsequent loose bowel movement. Don’t exceed 8 mg daily.
Children ages 9 to 11 or who weigh 28 to 43 kg (60 to 95 lb): 2 teaspoons or 1 tablet P.O. after first loose bowel movement, followed by 1 teaspoon or 1/2 tablet after each subsequent loose bowel movement. Don’t exceed 6 mg daily.
Children ages 6 to 8 or who weigh 22 to 27 kg (48 to 59 lb): 2 teaspoons or 1 tablet P.O. after first loose bowel movement, followed by 1 teaspoon or 1/2 tablet after each subsequent loose bowel movement. Don’t exceed 4 mg daily.

Pharmacodynamics
Antidiarrheal action: Loperamide reduces intestinal motility by acting directly on intestinal mucosal nerve endings; tolerance to antiperistaltic effect doesn’t develop. Drug also may inhibit fluid and electrolyte secretion by an unknown mechanism. Although it’s chemically related to opiates, it hasn’t shown any physical dependence characteristics in humans, and it possesses no analgesic activity.

Pharmacokinetics
Absorption: Absorbed poorly from the GI tract.
Distribution: Distribution isn’t well characterized.
Metabolism: Absorbed loperamide is metabolized in the liver.
Excretion: Excreted primarily in feces; less than 2% is excreted in urine.

Contraindications and precautions
Contraindicated in children younger than age 2, in patients hypersensitive to drug, and in patients for whom constipation must be avoided. Also, OTC use is contraindicated in patients with a fever exceeding 101° F (38.3° C) or if blood is present in the stool. Use cautiously in patients with hepatic impairment.

Interactions
Drug-drug. Opioid analgesics: May cause severe constipation. Avoid use together.

Adverse reactions
CNS: drowsiness, fatigue, dizziness.
GI: dry mouth; abdominal pain, distention, or discomfort; constipation; nausea; vomiting.
Skin: rash, hypersensitivity reactions.

Effects on lab test results
None reported.

Overdose and treatment
Effects of overdose include constipation, GI irritation, and CNS depression.
 Treatment is with activated charcoal if ingestion was recent. If patient is vomiting, activated charcoal may be given in a slurry when patient can retain fluids. Or, gastric lavage may be performed, followed by administration of activated charcoal slurry. Monitor patient for CNS depression; treat respiratory depression with naloxone.

Special considerations
• After administration via nasogastric tube, flush tube to clear it and ensure passage of drug to stomach.
• Monitor fluid and electrolytes if severe diarrhea occurs.
Breast-feeding patients
• It isn’t known whether drug appears in breast milk. Use cautiously in breast-feeding women.
Pediatric patients
• Drug is approved for use in children age 2 and older; however, children may be more susceptible to adverse CNS effects.

Patient education
• Warn patient to take drug only as directed and not to exceed recommended dose.
• Caution patient to avoid driving and other tasks requiring alertness because drug may cause drowsiness and dizziness.
• Instruct patient to call if no improvement occurs in 48 hours or if fever develops.

Reactions may be common, uncommon, life-threatening, or COMMON AND LIFE THREATENING.
◆ Canada only
◇ Unlabeled clinical use