The Food and Drug Administration approved the drug Juvisync, which combines Merck's diabetes pill Januvia with the popular cholesterol drug Zocor.
Patients with both diabetes and high cholesterol are at increased risk for heart disease, stroke, kidney disease and other chronic conditions.
The American Diabetes Association recommends all people with diabetes over 40 take a cholesterol-lowering drug like Zocor, known as a statin. But Merck scientists estimate that as many as 4 million diabetes patients over 40 are not following that recommendation.
About 20 million people in the U.S. have type 2 diabetes, which leads to difficulty controlling blood sugar, or glucose. Patients with the condition are at a higher risk of a number of complications.
"Perhaps one third of the nation's eligible patients with type 2 diabetes are not being treated with a statin, so here's a convenient tool for doctors to target glucose as well as cholesterol levels," said Dr. Sethu Reddy, Merck's director of clinical affairs for diabetes.
The approval revives one of Merck's best-selling drugs, Zocor, which was a blockbuster before it began competing with lower-priced generics in 2006. The drug is now available in nearly a dozen generic forms as simvastatin.
Juvisync will be available in six different dosage strengths, to accommodate patients with varying levels of cholesterol and diabetes.
Common side effects with the drug include stuffy nose and sore throat, headache, muscle and stomach pain.
Merck & Co. Inc. shares rose 43 cents to $31.85 in morning trading.