The aim of the study is to evaluate the therapeutic efficacy, safety and local tolerability of two different paracetamol-containing solutions in postoperative total hip replacement. They will be compared to placebo (a dummy treatment which contains no active ingredient).

Inclusion Criteria:

• ASA I, II or III and scheduled for elective total hip replacement, using a standard approach and a cemented implant.
• Moderate or severe pain within 4 hours after stopping the PCA in the morning of the first post-operative day.

Exclusion Criteria:

• Another acute or chronic painful physical condition
• Use of any other analgesics (within 24 hours), sedatives, or narcotic drugs as well as microsomal enzyme inducers
• Inability to use and understand Visual Analog Scale and Verbal Rating Score