Clinical analgesic assay of oral zomepirac and intramuscular morphine.

Zomepirac appears to be an unexpectedly effective oral, non-opioid analgesic. The relative potency of oral zomepirac is roughly 1/5 to 1/8 that of intramuscular morphine. Visual analogues of pain relief offer a reliable alternative to verbal categorical scales, and may provide some advantages in assays of peak drug effect, and in relatively small patient populations.