Doctors may be halting use of anti-tumor necrosis factor (anti-TNF) medications too early in rheumatoid arthritis (RA) patients who are set to undergo surgery, researchers at the Hospital for Special Surgery (HSS) in New York City have found.
Doctors may be halting use of anti-tumor necrosis factor (anti-TNF) medications too early in rheumatoid arthritis (RA) patients who are set to undergo surgery, researchers at the Hospital for Special Surgery (HSS) in New York City have found. Their research, which was presented at the American College of Rheumatology’s annual meeting last November, indicates that better timing could help minimize the risk of arthritis flare.
Guidelines currently recommend that doctors stop anti-TNF medications before surgery because they suppress the immune system.
Principal investigator Lisa Mandl, MD, a rheumatologist at HSS, and her colleagues focused on total knee replacement (TKR) surgery using data from the HSS Total Joint Replacement Registry. Of 194 patients with RA who underwent TKR surgery between June 2007 and May 2012, the researchers found that 86 (41.4%) were taking anti-TNFs, chiefly etanercept, adalimumab, and infliximab.
Examination of the participants’ medical charts showed that 86% documented that anti-TNFs were to be stopped before surgery and 74% identified a specific stop time, but the stop times were not based on how long a given medication is known to remain in the system after cessation. In fact, the stop times were all far too early.
Patients on etanercept were taken off the drug an average of 2.4 weeks before surgery, even though the medication has a half-life of just 3 to 5.5 days. Those on adalimumab stopped taking it an average of 4.6 weeks before surgery, though its half-life is1.4 to 2.9 weeks. Patients on infliximab halted medication an average of 4.9 weeks before surgery, far short of its half life of 1 to 1.7 weeks.
Despite the tendency to remove patients from anti-TNF medications too early, the researchers did not find a statistically significant difference in adverse events among patients receiving anti-TNFs and those not receiving them. The self-reported RA flare rate was higher among those taking anti-TNFs (22.4% vs. 16.9%), but the difference was not statistically significant.
"At least in this relatively small sample, it doesn't look like there are any increases in infections or blood clots or other problems that go along with these anti-TNFs, which is comforting for patients who are on these drugs who are going in for surgery," Mandl said in a press release.
However, she added that further investigation is required to determine whether keeping patients on the medications longer before surgery would improve patients’ performance after surgery.