Fig. 5

Doses of tapentadol taken over time. Tapentadol dosage taken at baseline and after 24 weeks for groups treated with um-PEA as add-on to tapentadol (um-PEA-TP group) or with tapentadol alone (TP group). Mean values ± S.E. Both groups reduced significantly their TP dosage between baseline and week 24 (p < 0.0001). There was a greater reduction (p < 0.0001) in favor of the um-PEA-TP group over the TP-only group. Statistical comparisons were performed with GLMM