We assessed the
analgesic efficacy of IV
propacetamol and
ketorolac in a double-blinded, placebo-controlled study involving patients undergoing total hip or knee replacement procedures. On the first morning after major
joint replacement surgery, 164 patients experiencing moderate-to-severe
pain were randomly assigned to receive an IV infusion of
propacetamol (2 g),
ketorolac (15 or 30 mg), or placebo (saline).
Patient-controlled analgesia with
morphine was made available as a "rescue"
analgesic on patient's request during the 6-h postdosing evaluation period. The median time to onset of
analgesia with
propacetamol (8 [95% confidence interval 6,10] min) was shorter than
ketorolac 15 mg (14 [7,16] min), and placebo (16 [8; not estimable] min) although the differences did not reach statistical significance. However, compared with
ketorolac 30 mg,
propacetamol had a shorter duration of
analgesia (3.5 [2;5.4] vs 6 [3.3; not estimable] h). Analysis of
pain intensity and
pain relief scores demonstrated that
propacetamol produced a significantly greater improvement in
pain relief than saline from 45 min until 5 h after the injection.
Propacetamol was not significantly different from
ketorolac 15 mg and 30 mg with respect to the main
analgesic efficacy variables during the 6-h assessment period. The most frequently reported adverse event with
propacetamol was injection site
pain (28% vs 19% for
ketorolac 15 mg, 29% for
ketorolac 30 mg, and 10% for placebo, respectively). In conclusion,
propacetamol (2 g IV) possesses a similar
analgesic efficacy to
ketorolac (15 or 30 mg IV) after total hip or knee replacement surgery.