Results There is good evidence for a role of central sensitisation in chronic OA pain in a subgroup of patients .
Biomarkers may be helpful for confirming the presence of central sensitisation , especially when there is diagnostic uncertainty .
Several non‐pharmacological and pharmacological treatments may be effective in OA patients with central sensitisation features .
Multimodal therapy may be required to achieve control of symptoms .
Summary Aims The aim of this non‐ systematic review was to provide a practical guide for clinicians on the evidence for central sensitisation in chronic osteoarthritis ( OA ) pain and how this pain mechanism can be addressed in terms of clinical diagnosis , investigation and treatment .
Clinical ly , a central sensitisation component in chronic OA pain can be suspected based on characteristic pain features and non‐pain features seen in other conditions involving central sensitisation .
Effectiveness and Tolerability of Tapentadol Prolonged Release Compared With Prior Opioid Therapy for the Management of Severe, Chronic Osteoarthritis Pain
Background Tapentadol prolonged release ( PR ; 100–250 mg twice daily ) has been efficacious and well tolerated for managing moderate-to-severe , chronic osteoarthritis hip or knee pain in phase 3 studies with washout of previous analgesic treatment . Objective The objective of this study was to evaluate the effectiveness and tolerability of tapentadol PR ( 50–250 mg twice daily ) after direct rotation from World Health Organization ( WHO ) step III opioids in patients with severe osteoarthritis knee pain who previously responded to WHO step III therapy but showed poor tolerability . Methods This open-label , phase 3b study ( NCT00982280 ) was conducted from October 2009 through June 2010 ( prematurely terminated due to slow recruitment and study drug shortages ) in clinical care setting s in Europe and Australia . The study population included patients with severe , chronic osteoarthritis knee pain who had taken WHO step III opioids daily for ≥2 weeks before screening , responded to therapy ( average pain intensity [ 11-point numerical rating scale-3 ( NRS-3 ) ] ≤5 at screening ) , and reported opioid-related adverse effects  as their reason for changing analgesics . Patients switched directly from WHO step III therapy to tapentadol . Patients received oral tapentadol PR ( 50–250 mg twice daily ) during 5-week titration and 7-week maintenance periods . Oral tapentadol immediate release ( IR ) was permitted ( ≤twice/day , ≥4 h apart ) for acute pain episodes due to index pain or withdrawal symptoms following discontinuation of previous opioids ( combined dose of tapentadol [ PR and IR ] ≤500 mg/day ) . This study was planned to evaluate conversion  to tapentadol PR , based on responder rate 1 ( percentage of patients with same/less pain [ NRS-3 ] versus Week −1 ) at Week 6 ( primary endpoint ) , adverse events ( AEs ) , and discontinuation rates . Equianalgesic ratios were calculated for tapentadol prior to WHO step III opioids ( PR and PR plus IR formulations ) . Results Of 82 patients enrolled , 63 received study medication . In the per- protocol population , responder rate 1 at Week 6 ( last observation carried forward ) was 94.3 % ( 50/53 ; P < 0.0001 vs. the null hypothesis rate [ < 60 % ] ) . Mean ( st and ard deviation ) pain intensity scores were 4.7 ( 0.66 ) at baseline , 2.5 ( 1.46 ) at Week 6 , and 1.8 ( 1.41 ) at Week 12 in the main analysis population ( change from baseline at Weeks 6 and 12 , P < 0.0001 ) . Tapentadol to transdermal buprenorphine equianalgesic ratios ( PR [ n = 48 ] , 262.9:1 ; PR plus IR [ n = 48 ] , 281.1:1 ) and tapentadol to oral oxycodone equianalgesic ratios ( PR [ n = 4 ] , 4.3:1 ; PR plus IR [ n = 6 ] , 4.6:1 ) were calculated for the main analysis population . In the safety population , prevalence of AEs reported as associated with prior opioids at Week −1 ( reasons for rotation ) and related to tapentadol treatment at Week 12 decreased over time ; the most common were nausea ( 46.0 vs. 24.1 % ) and constipation ( 31.7 vs. 7.4 % ) . Overall , 14.3 % of patients discontinued the study early ; reasons included AEs ( 9.5 % ) , lack of efficacy ( 3.2 % ) , and withdrawal of consent ( 1.6 % ) . Conclusions Significant improvements in effectiveness were observed for tapentadol PR ( 50–250 mg twice daily ) versus WHO step III opioids in patients with severe , chronic osteoarthritis knee pain who previously responded to WHO step III therapy . Equianalgesic ratios were calculated for tapentadol to transdermal buprenorphine and oral oxycodone and were in line with observations from previous phase 3 studies
Results There is good evidence for a role of central sensitisation in chronic OA pain in a subgroup of patients .
Biomarkers may be helpful for confirming the presence of central sensitisation , especially when there is diagnostic uncertainty .
Several non‐pharmacological and pharmacological treatments may be effective in OA patients with central sensitisation features .
Multimodal therapy may be required to achieve control of symptoms .
Summary Aims The aim of this non‐ systematic review was to provide a practical guide for clinicians on the evidence for central sensitisation in chronic osteoarthritis ( OA ) pain and how this pain mechanism can be addressed in terms of clinical diagnosis , investigation and treatment .
Clinical ly , a central sensitisation component in chronic OA pain can be suspected based on characteristic pain features and non‐pain features seen in other conditions involving central sensitisation .