Since the worldwide withdrawal of Merck & Co’s COX-2 inhibitor Vioxx, almost a half of people with chronic musculo-skeletal pain are using no medication at all and nearly two-thirds are confused about relative risks and benefits of different analgesic types, according to a patient group survey.

Arthritis Action Group (AAG) presented a survey during EULAR, the European Rheumatology meeting held Amsterdam 21-24 June, involving 1,204 patients and 604 primary care physicians from four European countries, Australia and Mexico, revealing widespread confusion over analgesic risks and benefits.

AAG Chairman Professor Anthony Woolf said chronic musculoskeletal pain affects more than a million people in Europe alone, impacting on productivity and quality of life, so the survey suggests huge numbers of people have unmet treatment needs.

Reasons behind a decision to take no medication at all include concerns about serious side effects perceived by 25% of patients themselves or in 22% of cases because their primary care physician (PCP) advised stopping pain treatment.

“Less than half of patients who do take medication seek medical advice if their painkillers - whether OTC or prescribed - don’t work” said Professor Woolf. “And up to 64% of them say they are confused by conflicting information and don’t know enough about pain medications.”

The same survey revealed a communication gap between patients and PCPs, with doctors underestimating levels of concern about side effects. Only 43% discussed potential treatment benefits and 30% or fewer discussed potential side-effects. Fewer than half were familiar with recently updated guidelines.

“There is a clear need for more effective communication around the value of pain control and about risks and benefits” he concluded. ”People need to know how to combine effective pain relief with other approaches to self-management of their condition.”

Meanwhile, the survey tallies with a study presented at EULAR showing post-Vioxx (rofecoxib) switch patterns in the Netherlands.

Researchers from the PHARMO record-linkage institute in Utrecht looked at 5,542 chronic COX-2 selective NSAID users’ drug-dispensing records over the nine months following Vioxx’s withdrawal. Of these only 26% continued on a coxib. Of the remainder, approximately one-fifth stopped analgesic treatment altogether, one fifth switched to a non-selective NSAID and one fifth switched to a non-selective NSAID plus a proton pump inhibitor while 34% switched to non-NSAID painkillers. Only 7% later switched back to a coxib.

Prescribing decisions were similar for GPs and rheumatologists although internists were twice as likely to prescribe proton pump inhibitors. Rheumatologists were more than twice as likely to switch patients back to coxibs than GPs or other specialists.

From Olwen Glynn Owen in Amsterdam