Many people who take the cholesterol-lowering statin drugs report that they cause muscle pain, but a randomized trial suggests that the pain is no different when they take a placebo pill.
In rare cases, statins are known to cause a severe muscle condition called rhabdomyolysis, in which skeletal muscle tissue is destroyed, leading to serious complications. But much more frequently, people complain that the drugs simply cause muscle pain.
Whether statins are responsible for the muscle pain, however, remains uncertain. Muscle pain has many causes and is common in the older age group using statins, so determining whether statins are causing the pain is not easy. Results from observational studies, along with many media reports, may have led some to unnecessarily discontinue a treatment that is potentially lifesaving.
This new study, published in BMJ, involved a series of what is known as n-of-1 clinical trials, a methodology that allows researchers to examine the results of treatment and placebo in individual patients, rather than studying them as a group. In effect, each patient serves as his or her own control.
Researchers assembled 200 people in England and Wales who had either stopped or planned to stop taking statins because of intolerable muscle pain. For a year, each patient randomly took either a statin or a placebo pill over six two-month periods. Half the time they received 20 milligrams of Lipitor, and the other half they got a look-alike dummy pill. Until the end of the study, neither the researchers nor the patients knew when they were taking the statin and when they were taking the placebo.
During the last seven days of each two-month phase, the researchers measured each patient’s pain daily using a validated 10-point visual pain scale, with 10 indicating the worst possible pain. They also tracked other aspects of daily life, including the patient’s general activity level, mood, comfort in walking, ability to pursue normal work activities, social relationships, sleep and enjoyment of life.
The study found no differences between the statin and placebo periods in either muscle pain or reports on daily life activities and moods. Nine percent withdrew because of pain while they were on statins, but so did 7 percent who were taking placebos, an insignificant difference.
“These studies are difficult to do,” said Dr. Henry N. Ginsberg, a professor of medicine at Columbia who was not involved in the work. “This one is done as well as you can, and it’s a nice one to talk about with patients. You can tell your patients, ‘They’ve done studies in people like you, and these people couldn’t tell the difference between placebo and medicine.’”
Three months after the final treatment, when the patients had been informed of their results, the researchers asked them whether they had restarted statins, or intended to, and whether they found their own trial result helpful in making their decision. Most of the patients said that the trial was helpful, and more than two-thirds reported that they planned to start taking statins again.
The lead author, Dr. Liam Smeeth, a primary care physician and professor of clinical epidemiology at the London School of Hygiene and Tropical Medicine, said that when people stop statins because of muscle pain “they’re missing out on the huge benefits — reducing the risk of heart attack or stroke by about a third. What we’ve shown is that among these people who gave up their medicine because of pain — and their pain was real — it wasn’t made worse by statins.”