Diphenoxylate is an opioid and acts by slowing intestinal contractions; the atropine is present to prevent drug abuse and overdose.
Diphenoxylate is used to treat diarrhea in adults; it is only available as a combination drug with a subtherapeutic dose of atropine to prevent abuse.
[2] Other adverse effects include numbness in the hands and feet, euphoria, depression, lethargy, confusion, drowsiness, dizziness, restlessness, headache, hallucinations, edema, hives, swollen gums, itchiness, vomiting, nausea, loss of appetite, and stomach pain.
[7] In the United States, drugs containing diphenoxylate combined with atropine salts are classified as Schedule V controlled substances.
[9] Diphenoxylate and atropine have been studied in small trials as a treatment for fecal incontinence; it appears to be less efficacious and have more adverse effects when compared with loperamide or codeine.