SoluMatrix® Diclofenac: Sustained Opioid-Sparing Effects in a Phase 3 Study in Patients with Postoperative Pain

Objectives. To evaluate opioid rescue medication usage and the opioid-sparing effect of low-dose SoluMatrix VR diclofenac developed using SoluMatrix Fine Particle Technology TM in a phase 3 study in patients experiencing pain following bunionectomy surgery. Design. Multicenter, randomized, double-blind, parallel- group study (NCT01462435). Setting. Four clinical research centers in the United States. Subjects. Four hundred twenty-eight patients aged 18 to 65 years who experienced moderate-to-severe pain following bunionectomy surgery. Methods. Patients were randomized to receive lowdose SoluMatrix diclofenac 35mg or 18mg capsules three times daily (35-mg group or 18-mg group), celecoxib 400mg loading dose followed by 200-mg capsules twice daily (celecoxib 200-mg group), or placebo capsules postsurgery. Patients were permitted to receive opioid-containing rescue medication as needed. Results. Significantly fewer patients who received SoluMatrix diclofenac 35mg or 18mg or celecoxib required rescue medication during 0-24h and > 24-48h postsurgery compared with placebo. Patients in the SoluMatrix diclofenac 35mg or 18mg groups or in the celecoxib group used fewer mean rescue medication tablets over 0-24h and > 24-48 h compared with placebo-treated patients. Patients in the SoluMatrix diclofenac 35mg and 18mg groups and in the celecoxib group also required rescue medication at later times and at slower rates compared with placebo- treated patients. No serious adverse effects occurred in patients receiving SoluMatrix diclofenac. Conclusions. SoluMatrix diclofenac at two dosage strengths demonstrated an opioid-sparing effect postoperatively in this phase 3 study. Summary. The opioid-sparing effect following lowdose SoluMatrix diclofenac (35mg or 18mg three times daily) administration was evaluated in patients experiencing pain following bunionectomy. Significantly fewer patients receiving SoluMatrix diclofenac or celecoxib (400mg loading, 200mg twice daily) required rescue medication during 0-24 h and > 24-48 h following bunionectomy compared with placebo. No serious adverse events were reported among patients who received SoluMatrix diclofenac. SoluMatrix diclofenac may reduce opioid usage in the postoperative setting in patients with acute pain.