Long-term use of Statin Medicines
How long should the patient take a statin drug? They are designed and intended to be taken indefinitely, but the initial rush to sign up at-risk people drowned out questions about how long the therapy should continue. We know the anti-inflammatory effects decline pretty much when the patient stops taking the statin medicine. The inhibition of cholesterol synthesis in the liver will last longer. But even a return to pre-therapy cholesterol production may not be as bad as it might seem at first. The blood vessels have not accumulated as much plaque as they would otherwise.
There has been speculation that the bulk of the benefits accrue in the first five years. That might sound too convenient to be true, but a long-term study in Scotland (West of Scotland Coronary Prevention Study) found men who took statins for five years during middle age still had benefits in old age. Compared to those who took placebos, the patients who took statins for five years had lower rates of cardiovascular disease two or more decades later.
It is true that the scientific evidence for long-term use is weaker than it is for short-term use. That’s because randomized clinical trials, the gold standard of testing drug efficacy and side effects, only last a few years at most. This isn’t true just for statin; it’s true for high blood-pressure medicines, diabetes medicines, and other medicines people use for decades. The science for long-term use exists but it is more from observational studies.
Any realistic consideration of this question must take into account whether patients continue to take their prescription over the years. Patients often quit their statin regimens, either because of side effects or laziness or forgetfulness or some other reason. It is also common for people to stop taking their statin and then starting again in the future. One observer described statin usage in the population as “dynamic”.
No authoritative medical association or professional group has publicly advocated truncating statin use after a certain number of years. Initial approval of a drug is based on randomized clinical trials and the safety and efficacy data generated from it. These trials are necessarily limited in time, so there are always questions about long-term use of a medicine which cannot be answered before approval. The problem with many clinical trials is that they are short-term (compared to how long patients will actually be using the drugs) and they focus on biochemical markers or levels as opposed to clinical end points (e.g. death, heart attack, stroke.) Over time data from real world patients (not in formal clinical trials) accumulates. The FDA has systems for collecting reports of adverse events related to medication, and sometimes drugs will even be pulled from the market if the risk is deemed high enough. This is how Baycol was removed from use a decade ago. The most widely used statins have been in general use so long now, used by millions of people around the world, that analysts have a good idea of how dangerous they are in long-term use. Again, no authoritative body has called for a moratorium on these drugs, either in general usage or after a decade in use by individual patients. Some doctors and patients do take drug holidays from many medicines, though.