TRENTON, N.J. (AP) -- Drugmaker Merck & Co. said Tuesday that it's recalling a combination cholesterol drug, wiping out the entire U.S. stock, due to packaging defects that could reduce effectiveness.
Merck said the recall covers all four dose strengths and every batch distributed since Liptruzet was launched last May.
Both active ingredients in the drug remain available separately, though.
Merck, the world's third-biggest drugmaker, said some of the foil pouches holding the pills may allow air and moisture inside. The company said there's a remote chance that could decrease the drug's effectiveness or otherwise change its properties, but that the recall is not due to any reports of patients being harmed.
Liptruzet combines two popular drugs that work in complementary ways to reduce levels of LDL, or bad cholesterol, a common strategy for preventing heart attacks and strokes.
Merck's own Zetia, known chemically as ezetimibe, decreases the amount of cholesterol absorbed from food. The other ingredient, atorvastatin, lowers the body's natural production of cholesterol.
Atorvastatin is the generic version of Lipitor, the cholesterol pill made by Pfizer Inc. that was the world's top-selling drug for nearly a decade until it got generic competition two years ago.
Merck continues to sell Zetia, and several companies sell inexpensive atorvastatin. Liptruzet costs more than $5.50 per pill, about the same as Zetia, while atorvastatin costs about 25 cents a pill.
The company, based in Whitehouse Station, N.J., said patients can continue taking any Liptruzet they have and should consult a doctor before stopping it. Merck plans to get Liptruzet back on the market as soon as possible.
According to a Merck spokeswoman, the Liptruzet packages were produced by a U.S. manufacturer under contract with Merck.