(ABC NEWS) -- Ranbaxy Pharmaceuticals Inc., the company that makes a generic version of the cholesterol-controlling medicine Lipitor, has agreed to stop producing the drug because it is unable to explain why some of the tablets are laced with tiny pieces of glass.
Millions of Americans take Lipitor and its generic versions to control their cholesterol, and it has become the fifth most popular medicine in the country. India-based Ranbaxy produces one of every three of the generic versions.
The Federal Drug Administration overnight said Ranbaxy has agreed to stop manufacturing Atorvastatin, a generic version of Lipitor.
"I think the quick message is that the company has real difficulties with quality control," Dr. Edward Boyer of the University of Massachusetts Medical School said.
The FDA says the company will stop production "until it has thoroughly investigated the cause of the glass particulates and remedied the problem."
"Consumers who are concerned that they may have received a recalled product should consult with their pharmacist where they bought the product to confirm whether they received a recalled product, should stop taking the product if it was recalled, and should consult with their pharmacist or physician about how to obtain an alternative product," the FDA said in a statement.
The government says it does not expect any immediate shortage because other companies make generic versions of Pfizer Inc.'s Lipitor.
Ranbaxy first issued recalls Nov. 9 because of glass contamination, which, according to the government and doctors, sounds worse than it is.
"This is not truly a threat to people's health," Dr. Boyer said. "Eating a pill that contains numerous particles of glass a millimeter in size or less is akin to eating a pill that contains small bits of sand in it."
Still, some experts say the glass could cause minor irritation of the digestive system.
The non-generic, brand-name Lipitor -- which many insurance companies no longer cover -- averages a little less than a dollar more per pill than the generic version. Before generic versions entered the market last year, Lipitor generated $600 million in sales every year.
Representatives from Ranbaxy did not return ABC News' request for comment.
The FDA said it has not received any complaints about sickness from Atorvastatin users. Still, the agency is concerned about the quality control at the factory in Punjab, India.