People who take opioids for pain relief for extended periods of time may need higher doses to ease their pain. They may develop tolerance to the drug and experience withdrawal symptoms if the medication is abruptly stopped. They become physically dependent on the drug.
Antibiotics most likely to cause C. diff infections are clindamycin, amoxicillin, ampicillin, and cephalosporins, and to a lesser extent, penicillin, erythromycin, and quinolones.
http://www.gastro.org/attachments/6401/1_CDiff_Overview_Design.pdf. 1  Clostridium difficile, or C. diff for short, is an infection from a bacterium, or bug, that can grow in your intestines and cause bad GI symptoms.  The main risk of getting C. diff infection is antibiotic use.