Patients with OA treated with tramadol had a 20%-50% higher risk of dying during the first year of treatment than did patients who were treated with NSAIDs, according to the results of a large, population-based study performed in British Columbia.
Within 1 year of starting treatment, 296 of 13,798 patients treated with tramadol had died, compared with 246 of 13,798 treated with naproxen, giving a death rate of 21.5 versus 17.8 per 1,000 person-years, and representing a 20% increase in all-cause mortality versus the NSAID (hazard ratio, 1.2).
Similar results were seen comparing tramadol with diclofenac and tramadol with cyclooxygenase (COX)-2 inhibitors, but with increasing death rates of 24.8 versus 19.5 per 1,000 person-years (HR, 1.3) and 23.6 versus 15.7 per 1,000 person-years (HR, 1.5), respectively.
However, all-cause mortality was lower with tramadol than with the opiate painkiller, codeine (21.5 vs. 25.5 per 1,000 person-years; HR, 0.8), reported Ms. Lingyi Li, a PhD student from the University of British Columbia, Vancouver, at the annual European Congress of Rheumatology, held online this year due to COVID-19.
This is not the first time that tramadol’s excess mortality risk has been highlighted. Indeed, just last year (JAMA. 2019;321[10]:969-82), researchers using The Health Improvement Network database reported found that tramadol was associated with higher all-cause mortality than two COX-2 inhibitors, celecoxib (31.2 versus 18.4 per 1,000 person-years) and etoricoxib (25.7 versus 12.8 per 1,000 person-years).
Ms. Li and associates’ data not only now add further weight to those findings, but also go a step further by also looking at other serious risks associated with tramadol’s use among patients with OA. “The objective of this study is to compare tramadol with other commonly prescribed pain relief medications on the risk of several severe outcomes, including mortality, cardiovascular diseases [CVD], venous thromboembolism [VTE], and hip fracture,” Ms. Li said during her virtual presentation.
Using sequential propensity score matching, the researchers compared data on patients in British Columbia during 2005-2014 with a first prescription of tramadol (56,325), the NSAIDs naproxen (n = 13,798) or diclofenac (n = 17,675), COX-2 inhibitors (17,039), or codeine (n = 7,813).
“For CVD, we found that there is a higher risk among tramadol users, compared with diclofenac [HR, 1.2] and COX-2 inhibitors [HR, 1.2], but not with naproxen [HR, 1.0] and codeine [HR, 0.9] users,” Ms. Li reported.
Similarly, the 1-year risk of VTE was significantly higher among tramadol users only when compared with diclofenac (HR, 1.5) and COX-2 inhibitors (HR, 1.7).
“For hip fractures, tramadol initiation was associated with an increased risk of hip fractures, compared with all NSAIDs, but not with codeine,” Ms. Li said. The risk of hip fractures was 40%-50% higher with tramadol versus naproxen (HR, 1.4), diclofenac and COX-2 inhibitors (both HR, 1.5).
“Our results suggest an unfavorable safety profile of tramadol use,” Ms. Li said, suggesting that “several guidelines on tramadol use in clinical practice might need to be revisited.”
According to a recent Cochrane review there is “moderate-quality evidence” that tramadol “has no important benefit on mean pain or function in people with osteoarthritis.” The authors of the review wrote that, while some patients might glean a benefit from treatment, the evidence suggests that “adverse events probably cause substantially more participants to stop taking tramadol.”
Current guidance on the use of tramadol varies. The American Academy of Orthopaedic Surgeons guidelines recommend its use in patients with symptomatic knee OA on a par with NSAIDs while the American College of Rheumatology guidance (Arthritis Care Res. 2020;72[2]:149-62) conditionally recommends that it be used only if there is no real alternative, such as a contraindication to NSAIDs or pain relief is ineffective.
Patients with rheumatic disease are increasingly taking opioid painkillers such as tramadol, with other data reported at the EULAR 2020 E-Congress showing a rise from 15% in 2007 to 25% in 2016 in the Catalonia region of Spain alone. A rise from 5% to 10% has previously been reported in the United States from 2003 to 2009.
With increasing rates of tramadol prescribing, the worry is that perhaps tramadol is not as safe a people think it is, as Thomas Schwenk, MD, pointed out when he reviewed the previous research showing excess mortality with tramadol (NEJM Journal Watch, March 2019).
“The opioid agonist tramadol often is prescribed for patients with osteoarthritis pain because it is thought to be safer than opioids or nonsteroidal anti-inflammatory drugs,” he observed. Dr. Schwenk, who is dean of the University of Nevada, Reno, added that the “results [of that study] suggest that tramadol is not as safe as some people believe.”
He suggested cautious prescribing: “Tramadol might be an option for patients in whom NSAIDs are contraindicated, but it should be prescribed as judiciously as traditional opioids.”
Responsible prescribing to avoid opioid misuse in patients with rheumatic diseases was also advocated in a EULAR press release from the congress. A study from Iceland was highlighted that found patients with inflammatory arthritis frequently did not stop taking opioids after the source of their pain had gone; in fact, their use went up despite being treated with tumor necrosis factor inhibitors.
“We would like to raise awareness of a responsible approach both by the prescribers and also the patients,” said John Isaacs, PhD, of the University of Newcastle (England). “In order to alleviate chronic pain, medications should in any case only be part of a comprehensive therapy program, in which doctors, psychologists, and physiotherapists work together.”
The study authors had no conflicts of interest.
SOURCE: Li L et al. Ann Rheum Dis. 2020;79[suppl 1]:118, Abstract OP0191.