Efficacy and Safety of Tapentadol Extended Release Tablets in the Treatment of Moderate to Severe Pain in Subjects With Knee Osteoarthritis

The purpose of this study was to examine a low and high dose of tapentadol extended release tablet taken orally twice a day to reduce pain in subjects suffering from chronic moderate to severe pain due to osteoarthritis of the knee during a 4-week period. Subjects steadily increased their dose up to the low (100 mg) or high (200 mg) dose. Pain relief was compared to subjects taking placebo tablets or oxycodone extended release tablet, 20 mg. The serum concentrations and safety of tapentadol and oxycodone were also examined.