A new fixed-dose combination (FDC) of etoricoxib and tramadol has shown promising results in relieving acute low back pain, according to a recent phase III clinical trial. The study, conducted at three clinical sites in Mexico, compared the efficacy and safety of etoricoxib 90 mg/tramadol 50 mg once daily to paracetamol 975 mg/tramadol 112.5 mg three times daily in adult patients with moderate to severe acute low back pain.
The primary outcome of the study was the change in pain intensity measured by the Visual Analog Scale (VAS). Secondary outcomes included assessments of disability using the Oswestry Disability Index (ODI) and the Roland-Morris Disability Questionnaire (RMDQ). The trial included 124 patients, with 61 randomized to the etoricoxib/tramadol group and 63 to the paracetamol/tramadol group.
Superior Pain Reduction with Etoricoxib/Tramadol
The results indicated that the etoricoxib/tramadol combination led to a greater reduction in pain intensity compared to the paracetamol/tramadol combination. On day 5 of treatment, the change in VAS score was -4.6 for the etoricoxib/tramadol group compared to -3.8 for the paracetamol/tramadol group (p=0.041). This statistically significant difference suggests a faster and more effective pain relief with the etoricoxib/tramadol combination.
Improved Disability Scores
Both treatment groups showed statistically significant improvements in disability scores as measured by the ODI and RMDQ questionnaires (p=0.001). However, the etoricoxib/tramadol group demonstrated a trend towards greater improvement in the bothersomeness to perform daily activities, as determined by the RMDQ (p=0.068).
Opioid-Sparing Effect and Safety
The etoricoxib/tramadol combination also demonstrated an opioid-sparing effect, with a 55.9% reduction in the daily dose of tramadol compared to the paracetamol/tramadol group. This is significant because it can lead to a lower incidence of opioid-related side effects such as nausea, vomiting, and drowsiness.
Regarding safety, 38 subjects reported at least one adverse event (AE). 16 patients (26.2%) were in etoricoxib/tramadol group, and 22 (34.9%) were in paracetamol/tramadol group. The severity of the adverse events was greater in paracetamol/tramadol group compared to etoricoxib/tramadol (41.5 vs. 10.5%), this difference was considered statistically significant (p=0.002).
Multimodal Analgesia for Acute Low Back Pain
The study's findings support the use of multimodal analgesia, which involves combining drugs with different mechanisms of action to achieve synergistic or additive effects. Etoricoxib, a selective COX-2 inhibitor, reduces pain and inflammation by inhibiting prostaglandin synthesis. Tramadol, an atypical synthetic opioid, relieves pain through opioidergic, noradrenergic, and serotonergic effects.
"The combination of etoricoxib/tramadol provides effective pain relief through multimodal management due to the different mechanisms of action of its components, achieving a faster reduction in pain intensity compared to conventional therapy," the researchers noted.
Implications for Clinical Practice
The results of this study suggest that the fixed-dose combination of etoricoxib and tramadol could be a valuable therapeutic option for managing acute low back pain. Its faster onset of action, opioid-sparing effect, and favorable safety profile may lead to improved treatment adherence and better patient outcomes. Further research is warranted to confirm these findings and explore the long-term benefits of this combination therapy.
