Feb 5 (Reuters) – Cholesterol-lowering statin drugs do not cause most of the side effects attributed to them on package inserts, a large analysis of past clinical trials found.
For most people, the benefits of statins greatly outweigh the risks, study leader Christina Reith of Oxford University in the UK said in a statement.
Her team analyzed data from more than 154,000 participants in 23 randomized trials that lasted at least 2 years, including 19 that compared any of five statins – atorvastatin (Lipitor), fluvastatin (Lescol), pravastatin (Pravachol), rosuvastatin (Crestor), or simvastatin (Zocor) – to placebos, and four trials that compared more intensive versus less intensive statin therapy.
While millions of people have for decades safely used statins to reduce their odds of heart attacks and strokes, many others at high risk for cardiovascular disease have avoided the medicines over fear of side effects, Reith said.
The drugs are known to cause myopathy – a muscle disorder – in about 1 of every 10,000 patients per year, mostly in the first year of treatment, according to a report of the study published in The Lancet.
Statins have also been associated with small increases in blood sugar levels.
But when the researchers looked at rates of more than five dozen other potential adverse side effects listed in statin package leaflets, they found slightly higher odds for only four of the 66 on the labels.
For the other 62, including memory loss, depression, sleep disturbance, erectile and sexual dysfunction, gastrointestinal issues, weight gain, nervous system impairments and other symptoms, there were no significant differences in rates between patients taking statins and those taking placebos.
“This means that while people may notice these problems whilst taking statins, there is no good evidence that they are caused by the statin,” the researchers said.
SMALL INCREASE IN A FEW SIDE EFFECTS
Statin users had a very small increase in risk – about 0.1% – for liver blood test abnormalities in general and in a specific test measuring liver enzymes. But there was no increase in liver diseases such as hepatitis or liver failure.
Changes in urine composition that could potentially be associated with urinary tract symptoms were present in fewer than 1% of patients in both groups, with a 0.3% absolute increase in risk with statins.
The risk of edema – swelling from excess fluid, mostly in the lower extremities – was less than 1.5% per year overall and only 0.07% higher with statin therapy.
“Statin product labels list certain adverse health outcomes as potential treatment-related effects based mainly on information from non-randomized studies which may be subject to bias,” Professor Sir Rory Collins of Oxford Population Health, the report’s senior author, said in a statement.
“Ongoing confusion and concern, not just in patients, but also many doctors regarding potential statin side effects, means that many people are not willing to start statins or (continue) them even if they’re at high risk of having either a first or recurrent heart attack or stroke, and may derive really significant benefit from them,” Reith said at a press briefing.
Statins in clinical trials have shown the ability not only to lower levels of bad cholesterol but to significantly cut the risk of heart attack and stroke.
Brian Williams, chief scientific and medical officer at the British Heart Foundation, said the findings should reassure not only patients and doctors but also government regulators, and called on them “to change the package inserts.”
“Nobody’s disputing the fact that patients get adverse effects throughout their life. The big question is, are they related to the drug that they’re taking?” Williams said at the briefing. And the answer with statins, “is in large part, no.”
(Reporting by Nancy Lapid; Editing by Bill Berkrot)
