Results from a Phase 3 study of intravenous (IV) tramadol showed that the treatment was beneficial for patients with moderate to moderately severe postoperative pain following bunionectomy surgery.

In this multicenter, double-blind, placebo-controlled trial, patients (N=409) were randomized 1:1:1 to a postoperative regimen of IV tramadol 50mg, IV tramadol 25mg, or placebo administered over 15 minutes at hours 0, 2, 4, and once every 4 hours thereafter (up to 13 doses). The primary endpoint of the study was improvement in Sum of Pain Intensity Difference over 48 hours (SPID48); secondary endpoints included SPID24, total consumption of rescue medicine, and Patient Global Assessment.

Results showed that the 50mg dose achieved the primary endpoint of statistically superior improvement in SPID48 compared with placebo (P=.005), as well all 3 key secondary endpoints (P<.01). In addition, the 50mg dose was associated with a statistically significant improvement in pain reduction at 30 minutes post-dose (the first assessment timepoint). As for the 25mg dose, the data showed intermediate results, with a dose response seen across the efficacy endpoints. 

The IV treatment was generally well-tolerated; nausea, vomiting, and somnolence occurred more often among IV tramadol-treated patients, however, these adverse events were considered mild or moderate.

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“We are greatly encouraged by the strong safety and efficacy results from our first Phase 3 trial, which support IV tramadol’s potential to provide an improved IV treatment option for postsurgical pain, and to fill a significant gap between IV NSAIDs and Schedule II opioids,” said Scott Reines, MD, PhD, Avenue’s Chief Medical Officer. “Moreover, the trial clearly defined the 50mg dose that will be applied in our second Phase 3 trial in patients following abdominoplasty surgery as well as in our ongoing safety trial.”

Tramadol is a centrally-acting synthetic opioid anaglesic with a mechanism of action that delivers analgesic efficacy similar to conventional opioids but with less potential for abuse and dependence. It is currently available in oral tablet and capsule formulations for the management of pain severe enough to require an opioid analgesic and for which alternative treatments are inadequate.

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