Statin use linked to few side effects

Statins -- the popular class of cholesterol-lowering drugs used widely to prevent recurrent heart disease or stroke as well as risk for having a first cardiac or stroke event -- appear to cause few side effects, according to new research reported in Circulation: Cardiovascular Quality and Outcomes.

Researchers conducted the largest meta-analysis on statin side effects to date, reviewing data from 135 previous drug studies to evaluate the safety of the seven statins on the market. They concluded "as a class, adverse events associated with statin therapy are not common."

Researchers noted that simvastatin and pravastatin, the generic names of the brands Zocor and Pravachol, were found to have the best safety profile in the class. This is particularly true when patients were prescribed low to moderate doses of those statins, said Huseyin Naci, M.H.S., the study's lead author and a doctoral candidate at the London School of Economics and Political Science and research fellow at Harvard Medical School's Department of Population Medicine.

Researchers also noted a 9 percent increased risk of diabetes among statin users. But according to a previous landmark study, 250 patients need to be treated with a statin for one case of diabetes to be diagnosed.

"I am concerned that patients may misunderstand this small increase in risk and stop adhering to their medications," Naci said. The proven ability of statins to significantly cut the rate of death and hospitalization in patients who have heart disease outweighs the "small increase in diabetes risk," he said.

Researchers reviewed trials published between 1985 and early 2013, which included almost 250,000 patients. On average, the trials lasted a bit longer than a year. Some compared one statin to another, while others compared a statin to an inactive placebo, which is often called a sugar pill or dummy pill.

The study also found that statins were not linked to an increase in cancer risk. However, the drugs were associated with a typically reversible increase in liver enzymes, which Naci said still resulted in a very low rate of actual liver toxicity in statin patients.

"Although the benefits of statins clearly outweigh risks at the population level, individualizing such benefits and risks is more difficult," he said. "This brings into sharp focus the importance of identifying the individuals who stand to benefit the most from statin therapy.

Although the risk of developing diabetes is low, what this risk would amount to over time is simply not known based on the existing evidence," Naci said.