Many foot-surgery patients experience intense pain for several days following removal of a bunion, one of the most common foot surgeries. The investigational pain medication tapentadol provided significant relief for patients who had this surgery, compared to those treated with placebo. Treatment with tapentadol also resulted in patients reporting fewer gastrointestinal side effects compared to those treated with an older, prescription pain reliever researchers announced.

Results from a phase III clinical study of tapentadol immediate release (IR) tablets, a novel, investigational, centrally acting oral analgesic, showed that patients receiving 50 mg, 75 mg, or 100 mg of the medication experienced significant relief in acute pain after bunionectomy, a standard foot surgery associated with predictable levels of moderate to severe pain.

The overall difference in the intensity of pain experienced by patients recovering from bunionectomy was examined over the first 12, 24, 48 and 72 hours after initiating treatment with tapentadol. All tapentadol IR treatment groups showed a statistically significant improvement in pain over patients who received placebo, over all of these time periods.

Johnson & Johnson Pharmaceutical Research & Development, L.L.C. (J&JPRD) presented these new data in a poster session at the 27th Annual Scientific Meeting of the American Pain Society (APS) in Tampa, Florida. Treatment with 100 mg of tapentadol IR resulted in 79 per cent of patients experiencing at least a 30 per cent improvement in pain intensity at 48 hours. This is comparable to the 78 per cent of patients who experienced the same percentage of improvement with 15 mg of oxycodone IR.

Compared with placebo, the incidence of adverse events was higher for tapentadol IR and oxycodone IR treatment groups with a dose-dependent pattern of increasing adverse events. The most common treatment emergent adverse events in both active treatment groups included nausea, vomiting, constipation, dizziness, and somnolence (drowsiness).

However, the overall incidence of gastrointestinal side effects was lower at all three tapentadol IR doses than with 15 mg of oxycodone IR: tapentadol IR 50 mg at 46 per cent, 75 mg at 46 per cent, and 100 mg at 59 per cent versus oxycodone IR 15 mg at 73 per cent.

"This phase III study has shown that all three doses of tapentadol IR were effective in providing analgesic relief of moderate to severe pain. Tapentadol patients reported a reduced incidence of some gastrointestinal side effects in comparison with a comparable dose of oxycodone, a standard pain treatment," said lead study author Charles Oh, MD, director, J&JPRD.

"We are encouraged by these results and are eager to continue to study tapentadol as a novel acute pain treatment option".

Tapentadol has a unique profile with two mechanisms of action, combining mu-opioid receptor agonism and norepinephrine reuptake inhibition in a single molecule. It is being developed in immediate-release formulation for acute pain and extended-release formulation for chronic pain.

Acute pain is viewed as a complex, unpleasant experience with emotional and cognitive, as well as sensory features that occur in response to tissue trauma and is one of the most common reasons why patients seek medical attention. Common sources of acute pain include trauma, surgery, labour, medical procedures, and acute disease states. According to the American Pain Foundation, more than 25 million Americans experience acute pain each year as a result of injuries or surgeries.