diphenoxylate hydrochloride and atropine sulfate

Action

Acts on smooth muscle of GI tract by decreasing peristalsis, which inhibits motility. (Small amount of atropine is added to reduce abuse potential.)

Availability

Liquid: 2.5 mg diphenoxylate and 0.025 mg atropine/5 ml

Tablets: 2.5 mg diphenoxylate and 0.025 mg atropine

Indications and dosages

➣ Diarrhea

Adults: Initially, 5 mg P.O. three to four times daily, then 5 mg/day as needed (not to exceed 20 mg/day). Decrease dosage when desired response occurs.

Children: Initially, 0.3 to 0.4 mg/kg P.O. (liquid only) daily in four divided doses. Decrease dosage when desired response occurs.

Dosage adjustment

• Elderly patients

Contraindications

• Hypersensitivity to drug

• Obstructive jaundice

• Diarrhea associated with pseudomembranous colitis or enterotoxinproducing bacteria

• Angle-closure glaucoma

• Concurrent MAO inhibitor use

• Children younger than age 2

Precautions

Use cautiously in:

• inflammatory bowel disease; prostatic hypertrophy; severe hepatic disease (use with extreme caution)

• concurrent use of drugs that cause physical dependence; history of physical drug dependence

• elderly patients

• pregnant or breastfeeding patients

• children (safety not established in children younger than age 12).

Administration

See Don't confuse brand name Lomotil with Lamictal (an anticonvulsant). Serious errors have been reported.

• Withhold drug if patient has severe fluid or electrolyte imbalance.

• Administer with food if GI upset occurs.

See Don't give within 14 days of MAO inhibitors.

Adverse reactions

CNS: dizziness, confusion, drowsiness, headache, insomnia, nervousness

CV: tachycardia

EENT: blurred vision, dry eyes

GI: nausea, vomiting, constipation, epigastric distress, ileus, dry mouth

GU: urinary retention

Skin: flushing

Interactions

Drug-drug. CNS depressants (including antihistamines, sedative-hypnotics, opioids): increased CNS depression

Anticholinergic-like drugs (including tricyclic antidepressants, disopyramide): increased anticholinergic effects

MAO inhibitors: hypertensive crisis

Drug-diagnostic tests. Amylase: increased level

Drug-herbs. Angel's trumpet, jimsonweed, scopolia: increased anticholinergic effects

Drug-behaviors. Alcohol use: increased CNS depression

Patient monitoring

See Assess for and report abdominal distention and signs or symptoms of decreased peristalsis.

• Watch for signs and symptoms of dehydration.

• Assess frequency and consistency of bowel movements.

Patient teaching

• Instruct patient to report persistent diarrhea.

• Caution patient to avoid driving and other hazardous activities until he knows how drug affects concentration and alertness.

• Tell patient that prolonged use may lead to dependence.

• As appropriate, review all other significant adverse reactions and interactions, especially those related to the drugs, tests, herbs, and behaviors mentioned above.