Beta-blockers were associated with less pain and lower opioid consumption in a case-control study of nearly 900 patients with osteoarthritis, Ana Valdes, PhD, and her colleagues reported in Arthritis Care & Research.
There is some mechanistic support for the association, which has been observed in other pain disorders, noted Dr. Valdes of the University of Nottingham (England) and her coauthors (Arthritis Care Res. 2016 Oct 1. doi: 10.1002/acr.23091).
“Adrenergic neurotransmission is an integral part of the pathways that regulate the response to pain and stress,” the investigators wrote. “The increase in alpha1-adrenoceptor expression after nerve and tissue injury plays a role in neuropathic pain syndromes, and beta2-adrenergic receptor modulates the response to morphine. ... Importantly, both in patients with fibromyalgia and in those with temporomandibular joint disorder the number of painful body sites and self-reported pain severity is significantly lower after beta blockade when compared to placebo.”The cohort was drawn from the Genetics of Osteoarthritis and Lifestyle (GOAL) study. Dr. Valdes and her associates examined the effect of beta-blocker use on pain as measured by the Western Ontario and McMaster Universities Arthritis Index (WOMAC) pain score in 873 patients with knee and/or hip osteoarthritis. All were already taking at least one antihypertensive drug. The presence of “joint pain” was defined as a WOMAC score of less than 75. The multivariate analysis adjusted for age, gender, body mass index, knee or hip OA, history of other joint replacement, anxiety, and depression. Patients were a mean of about 69 years old; 347 were taking a beta-blocker.
After adjusting for the confounders, those taking the drugs were 32% less likely to report joint pain (odds ratio, 0.68). The effect seemed time bound: For every year on a beta-blocker, patients had a 4% decline in the risk of joint pain. The benefit was of similar magnitude regardless of whether patients had joint replacement. Beta-blockers also reduced the rate of opioid prescription by 27% (OR, 0.73), the authors noted.
They also found a similar benefit to the use of adrenergic blockers in general, but not with alpha-blockers. No other class of antihypertensive drugs showed any association with joint pain or with prescription of analgesics.
“These results might raise some future research questions for the treatment of hypertension in individuals with joint pain. Current guidance [in both the United Kingdom and United States] state that beta-blockers should no longer be preferred as an initial therapy for routine hypertension and should be used only when there is a compelling indication other than blood pressure control (for example, angina or chronic heart failure). If confirmed in randomized controlled trials, the data presented here could suggest that, in people with chronic joint pain beta-blockers may be considered as part of their antihypertensive regimen.”
The study was funded by the Arthritis Research UK Pain Centre, the European League Against Rheumatism, and AstraZeneca. Dr. Valdes had no financial disclosure, but one coauthor reported owning AstraZeneca stock.