Diphenoxylate HCl/Atropine Sulfate

 Action Diphenoxylate, related to meperidine, decreases motility of GI tract. Atropine discourages deliberate overdosage of diphenoxylate.

 Indications Adjunctive therapy in treatment of diarrhea.

 Contraindications Obstructive jaundice; diarrhea associated with pseudomembranous enterocolitis or enterotoxin-producing bacteria; narrow-angle glaucoma; use in children < 2 yr.

 Route/Dosage

ADULTS: Initial dose: PO 5 mg qid. Individualize dose. CHILDREN 2 to 12 YR: PO 0.3 to 0.4 mg/kg/day in 4 divided doses.

 Interactions

Alcohol, barbiturates, CNS depressants, tranquilizers: May increase depressant action Monoamine oxidase (MAO) inhibitors: May precipitate hypertensive crisis.

 Lab Test Interferences None well documented.

 Adverse Reactions

CV: Tachycardia. CNS: Dizziness; drowsiness; sedation; headache; malaise; lethargy; restlessness; euphoria; depression; numbness of extremities; confusion. DERM: Pruritus; angioneurotic edema; urticaria; dry skin and mucous membranes; flushing. GI: Dry mouth; anorexia; nausea; vomiting; abdominal discomfort; paralytic ileus; toxic megacolon; pancreatitis; constipation. GU: Urinary retention. OTHER: Swelling of gums; anaphylaxis; hyperthermia.

 Precautions

Pregnancy: Category B. Lactation: Excreted in breast milk. Children: Contraindicated in children < 2 yr. Greater risk of atropinism, especially with Down syndrome. Diarrhea: Do not give for diarrhea associated with organisms that penetrate the intestinal mucosa (ie, Salmonella, Shigella), acute Crohn's disease or pseudomembranous colitis caused by antibiotic therapy. Notify physician and discontinue therapy for abdominal distention or other untoward symptoms. Fluid/electrolyte imbalance: Dehydration may contribute to adverse effects, especially in young children. If dehydration or electrolyte imbalance occurs, may need to discontinue therapy until condition is corrected. Hepatic impairment: Use with extreme caution; may precipitate hepatic coma.

 Administration/Storage

• May administer drug with food if GI irritation occurs.
• Administer liquid form to children 2 to 12 yr.
• Tablets may be crushed and administered with fluid.
• Store in tightly closed, light-resistant container at room temperature.

 Assessment/Interventions

• Obtain patient history, including drug history and any known allergies. Note if patient is currently using MAO inhibitors (discontinuation may be necessary).
• Assess frequency and consistency of stools before and throughout therapy.
• Assess skin turgor and monitor fluid and electrolyte status during therapy.
• If signs of dehydration occur (poor skin turgor, decreased urine output, orthostatic hypotension, pulse changes, weight loss), notify physician.
• If signs and symptoms of toxic megacolon occur (abdominal pain, distention), notify physician.

 Patient/Family Education

• Advise patient to continue taking drug until diarrhea has stopped for 24 to 36 hr. Discontinuing medication earlier may result in relapse or return of diarrhea.
• Instruct patient to notify physician if fever and palpitations occur or when diarrhea persists or becomes malodorous or bloody.
• Tell patient to take sips of water frequently, suck on ice chips or sugarless hard candy or chew sugarless gum if dry mouth occurs.
• Instruct patient to avoid intake of alcoholic beverages or other CNS depressants.
• Advise patient that drug may cause drowsiness and to use caution while driving or performing other tasks requiring mental alertness.