The FDA approved the cholesterol-fighting drug Liptruzet Friday, despite criticism from cardiologists that studies have not shown the drug to be effective in lowering patients' chances of developing heart disease.

“This is extremely surprising and disturbing,” Dr. Steven E. Nissen, chairman of the department of cardiovascular medicine at Cleveland Clinic, told The New York Times.

The drug is a combination of Merck’s Zetia, which lowers low-density lipoprotein (LDL), with the generic version of Pfizer’s bestseller Lipitor that lost its patent protection in 2011.

Zetia and Vytorin, which combined Zetia with the older statin Zocor, have been on the market for a decade despite a lack of evidence that the drugs are capable of reducing heart disease.

The FDA defended the decision, saying “Liptruzet is a combination of two currently marketed drugs that effectively lower elevated levels of LDL cholesterol,” according to The New York Times.

In particular, Liptruzet is designed to target the production of cholesterol in the liver as well as inhibiting the absorption of cholesterol in the digestive tract.

According to Medical News Today, Merck has admitted that Liptruzet has not been shown to lower the risk of cardiovascular disease, including stroke and heart attack.

Forbes reports Nissen as stating that the move “does not make any sense,” saying that he finds it “astonishing” that the FDA would “approve another combination product with a drug that has been on the market for a decade and has not been shown to improve cardiovascular outcomes.”

Such a decision, Nissen argues, reflects a focus not on the endgame of curing cardiovascular disease, but rather a distraction on “surrogate endpoints” such as lowering cholesterol levels.

The approval could offer a boost to Mercks’ flagging cholesterol franchise, which includes a fall of sales of both Vytorin and Zetia since 2007 from annual combined sales of $5 billion to $4.4 billion in 2012, according to company filings.

In all, more than 42 million Americans suffer from high cholesterol, according to Medical News Today, with 63 million more living with borderline high cholesterol.