However, the heterogeneity in methods and, in particular,
the definitions of the primary end points, as well as
the variability in IV acetaminophen dosing regimens did
not permit a formal meta-analysis with pooling of
results. IV acetaminophen use was not associated with
increased adverse events compared with placebo within
the limited median follow-up duration for the placebo
studies analyzed being no longer than 3 days and usually
294 • macario and royal
just 1 day. When prescribing IV acetaminophen for
surgical pain, attention must be paid to patients at risk
for hepatotoxicity.