The number of people buying prescription drugs rose 8.3 percent last year to $274.9 billion, mainly attributed to the Medicare drug benefit, increased use of generic medicines and new treatments for diseases such as cancer and diabetes. According to the report released late Thursday by IMS Health, the drug sales growth is however expected to dampen a bit in 2007.

As the Medicare drug benefit is annualized and more generic products enter the market, it is anticipated that the drug sales will remain in a compounded annual rate of between 6 percent and 9 percent through 2010.

IMS Health is the world's leading provider of market intelligence to the pharmaceutical and healthcare industries. Business Wire quotes Diana Conmy, corporate director, IMS Market Insights as saying, "Demand for pharmaceutical products in the world's largest pharmaceutical market grew significantly for the third straight year."

"Legislative attempts to control drug expenditures, the increased influence of payers to drive more cost-effective healthcare, generics competition, and the introduction of new biosimilars will impact U.S. prescription growth over the next five years," she added.

As compared to the year 2005, when U.S. drug sales rose 5.8 percent to $253.7 billion the scenario changed in the year 2006 with the advent of Medicare drug benefit that offered prescription coverage to some individuals who were previously uninsured or underinsured.

According to the Friday's report, prescriptions allotted through the Medicare drug benefit accounted for 17 percent of retail prescriptions by the end of the year. Additionally, the sales of unbranded generics rose 22 percent to $27.4 billion.

The sudden rise was attributed to prescriptions for medicines such as the copycat versions of cholesterol agent Zocor and antidepressant Zoloft. The IMS also monitored the performance of certain drugs and found that cancer agent Sutent from Pfizer Inc. and diabetes treatments such as Eli Lilly and Co.'s Byetta and Merck and Co.'s Januvia did very well in sales.