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Polypharmacy and Adverse Events in RA

Polypharmacy is a valuable predictor of clinical outcomes in patients with rheumatoid arthritis (RA), a new study found. Researchers evaluated whether polypharmacy is associated with treatment response and serious adverse events (SAEs) in patients with RA using data from the British Society for Rheumatology Biologics Register (BSRBR-RA). A logistic regression model was used to calculate the odds of a EULAR “good response” after 12 months of biologic therapy by medication count. Cox proportional hazards models were used to identify risk of SAEs. Among the findings:

  • The analysis included 22,005 patients, of which 83% were initiated on biologics.
  • Each additional medication reduced the odds of a EULAR good response by 8% and 3% in the adjusted model.
  • There were 12,547 SAEs reported in 7,286 patients.
  • Each additional medication equated to a 13% increased risk of an SAE and 6% in the adjusted model.

Citation:

Bechman K, Clarke BD, Rutherford AI, et al. Polypharmacy is associated with treatment response and serious adverse events: Results from the British Society for Rheumatology Biologics Register for Rheumatoid Arthritis. [Published online ahead of print April 14, 2019]. Rheumatology. doi:10.1093/rheumatology/kez037.

Commentary:

Patients with RA have a risk of polypharmacy which increases as they age. They may, for example, take multiple medications for treatment of the disease, pain, other comorbidities, and even side effects from treatment. This study used a national monitoring registry in the UK to look at the association between polypharmacy and disease outcome as well as adverse effects in patients taking <5, 6-9, and ≥10 medications. As expected, side effects increased with increasing number of drugs. Patients who were taking more medications were also less likely to achieve a EULAR good response at 1 year. This may in part be due to the use of the BSRBR-RA registry, which looks at patients on biologics and therefore may have more severe disease. The study does not suggest a causal relationship between polypharmacy and worse RA outcome, nor that reducing the number of medications will improve RA outcome. However, especially in our patients with RA, a complex medical condition, as well as other comorbidities, the we should be aware of additional risks associated with polypharmacy. — Arundathi Jayatilleke, MD