Updated

Pfizer Inc. on Wednesday declined to comment on reports it hopes to start marketing an over-the-counter version of its cholesterol drug Lipitor, the world's biggest-selling prescription drug, after the original version loses patent protection in November.

The Wall Street Journal reported that Pfizer hopes to get the Food and Drug Administration to approve a version of Lipitor that could be dispensed without a doctor's prescription. Lipitor brings the New York-based drugmaker about $11 billion in annual revenue, and sales are already declining as cheaper generic versions go on sale in some overseas markets. The U.S. patent supporting the drug expires Nov. 30, which will allow generics to reach the market and eat into Pfizer's sales. The company could keep more of its revenue if it could sell a less-expensive OTC version.

A month's supply of Lipitor costs about $150, and generics are expected to cost about $10 per month in the U.S.

"We can confirm that we have strategic plans in place for Lipitor's loss of exclusivity and will comment no further at this time," Pfizer spokesman Ray Kerins said.

Dr. Nieca Goldberg, a cardiologist and medical director at New York University's Center for Women's Health, said she has some concerns about Lipitor being sold over the counter.

"I have concerns about people picking up the medicine like they would Maalox or Tums," Goldberg said. "We routinely follow up on liver tests for patients who are on cholesterol-lowering meds. And just because it's over-the-counter, doesn't mean you don't have to be concerned with medication or food interactions."

Goldberg said it's possible a lower dosage of Lipitor would be sold over-the-counter than the one that is prescribed in a doctor's office, and for some patients, that lower dosage will not be enough to combat their cholesterol problems.

She also worries that patients who opt to buy Lipitor over-the-counter would have to pay out-of-pocket, as it likely wouldn't be covered by insurance.

The Journal cited unnamed sources in its report. It said the world's biggest drugmaker would have a difficult time getting an OTC version approved, as some of its competitors have tried to follow the same course with other statin drugs — a class of cholesterol drugs that includes Lipitor — and they have not been successful.

The Associated Press contributed to this report.