verall, 12 of 14 placebo-controlled studies found that
patients receiving IV acetaminophen had improved analgesia.
When compared with IV parecoxib, IV metamizol,
or oral ibuprofen, IV acetaminophen was found to have
similar analgesic outcomes as the active comparator in 7
of the 8 studies. Parecoxib is a cyclo-oxygenase (COX)-
2-specific anti-inflammatory agent not approved in the
U.S.A. Metamizol is a nonsteroidal anti-inflammatory
drug removed from the U.S. market in the 1970s because
of its side effect profile, particularly agranulocytosis.