Rethinking Pain Management in Psoriatic Arthritis

Despite the use of biologic therapy, pain ranging from mild to severe is a persistent problem for psoriatic arthritis patients, researchers reported at EULAR 2017.

Pain may persist due to several factors:  Some patients may not have responded to treatment possibly suggesting the need to switch to another drug with a different mechanism of action; or, pain may be due to inflammation; muscle loss due to age; or, tendinitis, osteoarthritis and mechanical joint arthritis which can worsen with weakness and deconditioning.

“For people on established biologic therapy for at least a few months who were previously on TNF inhibitors, we found roughly a third of patients had mild pain, a third had moderate and a third had quite severe pain,” said Dr. Philip G. Conaghan, University of Leeds, who presented this study during the meeting in Madrid. “We’ve got to start focusing beyond recommendations to treat inflammation and instead, look at the patient as a whole. Do we need new drugs or do we need to consider muscle strengthening and other things that are going to help the patient cope with their pain?”

Dr. Conaghan and colleagues conducted two surveys of patients from 13 countries who were treated by rheumatologists and dermatologists. Patients answered questions that covered demographics, intake of non-prescription pain medication, work status, health-related quality of life (HRQoL), impairment in physical function (HAQ-DI), and impairment in work productivity and activity. Patient reported pain was stratified using tertiles of the SF-36 ‘Bodily Pain’ (BP) subdomain.

The first survey, SF-36, was a 36-item questionnaire on non-pain issues, such as physical functioning, general health, vitality, social functioning, physical, emotional and mental health. The results of this survey were clinically and statistically significant (p <0.0001).

Using a second questionnaire (EQ-5D), researchers assessed the impact of residual pain on health-related quality of life, mobility, self-care, usual activities, and anxiety/depression, all of which were significantly worse with a higher level of pain (p<0.0001).

Of 782 psoriatic arthritis patients receiving biologic therapy (primarily anti-TNF treatment) for at least three months 33.1% reported having no or mild pain (BP: >75 to 100); 30.1% had moderate pain (BP: >52 to ≤75) and, 36.8% reported being in severe pain (BP: 0 to ≤52: 36.8%).

More severe pain was associated with increased use of prescription NSAIDS (p=0.0026) and opioids (p=0.0065), as well as non-prescription pain medication (p<0.0001).

The more severe the pain, the greater the disability, activity impairment, overall work impairment, work time missed and impairment while working due to psoriatic arthritis (all p<0.0001). Working age patients (<65) who suffered from severe pain were more likely to be unemployed or retired early (19% of patients with mild pain; 10% of patients with moderate pain; and 58.3% of patients with severe pain).

The survey showed that pain is common among psoriatic arthritis patients receiving biologic therapy and the more the severe the pain, the greater impact on physical functioning, engagement in activities and work productivity.  

“In short, despite modern therapies largely with TNF inhibitors, we have seen a significant remnant of pain - which is one of the most important things patients tell us in every survey. This survey demonstrated that indeed pain impacts their life in terms of quality and work. So, one of the big questions out of this study is why is there so much pain despite these therapies?” Dr. Conaghan asked.

The results suggest a need for treatments that provide fast and sustained improvement in pain to reduce the impact pain has on the quality of life of patients, as well as societal costs, he stated.

References:

P. G. Conaghan, V. Strand, R. Alten, et al. “Pain Still Remains a High Unmet Need Among Psoriatic Arthritis Patients Receiving Existing Biologic Treatment: Results From A Multi National Real-World Survey,” EULAR 2017. Abstract:  OP0107