MORRISTOWN, N.J. — A subsidiary of Watson Pharmaceuticals has begun shipping a generic version of Lipitor in Canada.

The specialty pharmaceutical company said Wednesday that its Cobalt Pharmaceuticals subsidiary has received a notice of compliance from Health Canada to market atorvastatin calcium tablets in the 10-, 20-, 40- and 80-mg strengths. Watson said it has initiated shipment of the cholesterol-lowering drug.

Atorvastatin calcium is the generic equivalent to Pfizer’s Lipitor tablets and is indicated to reduce the risk of heart attack, stroke, certain kinds of heart surgeries, and chest pain in patients with heart disease or several common risk factors for heart disease, according to Watson.

For the 12 months ending in March, Lipitor had total Canadian sales of about $1 billion for, according to IMS Health figures cited by Watson.

"We are very pleased that our Cobalt organization will be adding this important therapy to its expanding portfolio of products," Watson president and chief executive officer Paul Bisaro said in a statement. "Cobalt is well-positioned to maximize the launch of the largest product to be offered as a generic in the history of the Canadian generic pharmaceutical industry."