Buy Xanax 3mg overnight online cash on delivery process, Some opioids, such as codeine and hydrocodone, are included in cough syrups and medications to suppress a persistent cough. They work by reducing the urge to cough. Diarrhea Control: Certain opioids, like loperamide, can be used to treat diarrhea. They slow down the movement of the intestines, reducing the frequency of bowel movements.