Beta-blockers fail to show analgesic effect in knee osteoarthritis

Takeaway

• A prospective cohort study nixes a link between β-blockers and pain reduction in patients with symptomatic knee osteoarthritis (KOA).

Why this matters

• Small randomised controlled trials previously suggest that β-blockers are associated with improved analgesia in other pain conditions.

Study design

• Multicentre prospective longitudinal observational study of symptomatic KOA in at least 1 knee (n=1168; Kellgren-Lawrence grade ≥2 with frequent pain).
• β-blocker users were compared with other antihypertensive users (e.g., calcium channel blockers, diuretics) for pain reduction.
• β-blocker and other medications usage was confirmed by direct examination by study personnel.
• Funding: NIH; Merck & Co., Inc., Kenilworth, NJ, USA; Novartis Pharmaceuticals Corporation; GlaxoSmithKline; Pfizer, Inc.

Key results

• 15% of cohort reported β-blocker use; 33% reported other antihypertensive users.
• On Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC pain scores; range, 0-20 with higher numbers indicative of worse pain), no differences were found between β-blocker users (5.2; 95% CI, 4.7-5.8) and other antihypertensive users (4.9 [95% CI, 4.6-5.2]; within-person difference of 0.1 [95% CI, −0.3 to 0.4]).
• No differences between β-blocker users and users of other antihypertensives in:
  • proportion reporting widespread joint pain (pain affecting both sides of the body above and below the waist), and
  • proportion with reported use of strong prescription pain medication.

Limitations

• Observational design.