Diphenoxylate
Mechanism :
The mode of action of diphenoxylate in the bowel is similar to that of morphine and related drugs. Gastrointestinal propulsion is inhibited through a direct action on the smooth muscle, resulting in a decrease in peristaltic action and a consequent increase in transit time.
Indication :
- Adjunct in the management of diarrhea
- In patients with colostomies and ileostomies to reduce fluidity and frequency of stools.
Contraindications :
Known hypersensitivity to diphenoxylate or atropine; jaundice; pseudomembranous enterocolitis; diarrhea caused by enterotoxin producing bacteria.
Dosing :
Not recommended in children under 2 years of age.
>2-13 years:
0.3 to 0.4 mg/kg PO daily in divided doses.
>13 years:
5 mg diphenoxylate/0.05 mg
atropine every 6 hours PO. Max: 20 mg diphenoxylate.
Adverse Effect :
Nausea, drowsiness, coma, lethargy, restlessness, dizziness, headache, blurring of vision, depression, euphoria, confusion, paresthesia, malaise, respiratory depression, vomiting, anorexia, nausea, abdominal bloating, cramps, paralytic ileus, toxic megacolon, pancreatitis, anaphylaxis, pruritus, atropine effects such as dryness of the skin and mucous membranes, hyperthermia, tachycardia, urinary retention and flushing.
Interaction :
Barbiturates, Tranquilizers and Alcohol: May potentiate the action of barbiturates, tranquilizers and alcohol.
Meperidine: Since the chemical structure of diphenoxylate is similar to that of meperidine, the concurrent use with MAO inhibitors may in theory precipitate a hypertensive crisis.
Hepatic Dose :
Use with extreme caution in patients with abnormal hepatic function and in advanced hepatorenal disease.