Certain pain-relieving drugs that belong to a group of medications called COX inhibitors may impair the ability of human blood cells to rid themselves of cholesterol, according to research published Jan. 23 in the journal Arthritis Research & Therapy.
The finding suggests an explanation for an increased risk of heart attacks in people who used Vioxx and Bextra called COX-2 inhibitors and could help the pharmaceutical industry develop new arthritis pain drugs.
The researchers, including two at Winthrop-University Hospital in Mineola, wanted to determine whether something other than blood clots contributed to heart problems linked to Vioxx.
Dr. Allison Reiss, head of the inflammation section of Winthrop’s Vascular Biology Institute, was the lead researcher. Dr. Steven Carsons, chief of Winthrop’s Division of Rheumatology, Allergy and Immunology, also participated.
The study found excess cholesterol and blood clots together may have caused side effects linked to Vioxx and Bextra.
Vioxx and Bextra were taken off the market in 2004 and 2005, respectively. Vioxx showed a higher risk of heart attack and stroke in people using it longer than 18 months. Bextra sparked concerns about life-threatening skin reactions and cardiovascular problems.
The researchers found chemical equivalents of certain COX inhibitors diminished naturally occurring prostaglandins and caused lipid buildup in human blood cells that they studied in culture. “The remarkable thing was that the drugs all compromised the mechanism that rids cells of cholesterol,” Reiss said.
Adding back prostaglandins helped restore the cholesterol balance.
Pfizer Inc., which sold Bextra, issued a statement: “This study represents an interesting new theory about why all NSAIDS [non-steroidal anti-inflammatory medicines], including selective and non-selective, may impact heart health.” Pfizer said further work is needed.
A statement from Merck and Co. Inc., which made Vioxx, said: “At this time, Merck has not yet had the opportunity to examine the paper’s methodology or the authors’ conclusions with the rigor appropriate for the review of any scientific study, particularly one which seeks to draw conclusions about human health from experiments performed in a laboratory rather than from clinical trials in humans.”