In a development which nudged the company's shares values higher, Walgreen Co, America's top ranked and largest drugstore chain, posted a nearly 20% surge in its quarterly profits on the back of increased sales of prescription drugs and more demand for flu shots, which overshadowed consumer cut backs on other discretionary products.

The growth posted has been marginally better than the estimates pegged by analysts, and Walgreen shares managed to record a 3.4% rise in pre-market trading to hit a new high of $37.90.

The company has been much ahead of its rivals in administering shots for the dreaded H1N1, which has led to an increase in pharmacy sales during the reported quarter. So far this year, Walgreen and its Take Care in-store clinics have handled as many as 5.4 million seasonal flu shots, as compared to the 1.2 million for the entire flu season that were recorded for last year.

For the quarter up-to November 30 for the current fiscal year, the company posted earnings of $489 Million, or 49 cents per share, which is a substantial rise from the figure of $408 Million, or 41 cents a share, posted for last year's same period.

Currently, Walgreen operates over 7,140 drugstores, and is going ahead with its plan of adding wine and beer to its stores in order to become more convenient.