These effects may occur especially in children. Controlled Substance Diphenoxylate HCl and atropine sulfate tablets are classified as a Schedule V controlled substance. Diphenoxylate hydrochloride is chemically related to the narcotic analgesic meperidine. In doses used for the treatment of diarrhea, whether acute or chronic, diphenoxylate has not produced addiction.
Diphenoxylate hydrochloride is devoid of morphine-like subjective effects at therapeutic doses.
At high doses, it exhibits codeine-like subjective effects. The dose which produces antidiarrheal action is widely separated from the dose which causes central nervous system effects. The insolubility of diphenoxylate hydrochloride in commonly available aqueous media precludes intravenous self-administration. Since addiction to diphenoxylate hydrochloride is possible at high doses, the recommended dosage should not be exceeded. Therefore, diphenoxylate has the potential to prolong the biological half-lives of drugs for which the rate of elimination is dependent on the microsomal drug metabolizing enzyme system.