Why Statins Don't Always Work

Statins can lower cholesterol most times

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) For some patients, statins simply aren't effective at lowering their high cholesterol. Now scientists think they may have figured out why the cholesterol-lowering drugs don't work well in some patients.

Three bile acids produced by gut bacteria have been found in patients who did not respond well to common cholesterol medication Zocor (simvastatin).

"Get your cholesterol checked regularly."

Rima Kaddurah-Daouk, lead author, an associate professor in Duke School of Medicine's department of psychiatry and leader of the Pharmacometabolomics Network, said determining the effects of drugs and how individuals respond amounts to personal medicine.

She said that the benefit of statins may be partly related to the type of bacteria in our guts.The reason we respond differently is not only because of genetic makeup, but also gut microbiome, she said.

Researchers gathered data from a subset of patients already enrolled in the large-scale Cholesterol and Pharmacogenetics study. They then selected 100 patients from the study whose "bad" LDL cholesterol fell dramatically after taking simvastatin, 24 who had a fairly good response to the drug and 24 who showed little benefit.

Investigators analyzed blood work taken from participants before they began the drug to search for bile acids and fat-like substances called sterols that are involved in the body's break-down and use of cholesterol.

They found that in the group that had a strong favorable response to the drug, three bile acids produced by gut bacteria played a role. In patients who responded poorly to the statin, five bile acids were found.

The researchers suggested that the bile acids and statins may share transporter routes to the liver and intestines and remain in competition for the route. Because of this dynamic producing more or less of certain bile acids could improve or diminish the drug's effects.

A blood screening for specific bile acids could pinpoint who would respond to simvastatin and who would not. It also is possible that strategies could be developed to manipulate gut microbiome using probiotics to spur different gut bacteria, which could boost the medication.

The finding was recently published in journal PLoS ONE.

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Review Date: 
October 21, 2011
Last Updated:
October 21, 2011