NOT KNOWN FACTS ABOUT FENTANYL MEDICAL USAGE

fentanyl, cyproheptadine. Both improves toxicity from the other by pharmacodynamic synergism. Modify Therapy/Check Intently. Coadministration of fentanyl with anticholinergics could maximize risk for urinary retention and/or extreme constipation, which may bring on paralytic ileus.butorphanol decreases effects of fentanyl by pharmacodynamic antagon