Last year, nearly 80% of the 4 billion prescriptions written in the US were dispensed for generic medicines, and savings gained from the use of generics soared 22% over 2010's level, says a new report.

US savings from the use of generic prescription drugs have risen to a current rate of $1 billion every other day, totalling $193 billion in 2011 and more than $1 trillion over the last 10 years, according to the study, which was conducted by the IMS Institute for Healthcare Informatics for the Generic Pharmaceutical Association (GPhA).

Despite accounting for nearly 80% of all prescriptions written, generics accounted for just 27% of total US drug spending last year, the study adds. Savings from newer generic medicines - those that have entered the market since 2002 - continue to increase "exponentially," totalling $481 billion over the past 10 years, while generic versions of central nervous system (CNS) drugs such as antidepressants and anticonvulsants, and cardiovascular drugs, accounted for 57% of savings last year, it adds.

Governments and payers around the world are now seeing the benefits of an unprecedented number of patent expiries on some of the research-based industry's biggest successes. These include Pfizer's Lipitor (atorvastatin), the world's top-selling medicine, which lost its patent exclusivity in November 2011, while Eli Lilly's Zyprexa (olanzapine) and Sanofi's Plavix (clopidogrel) both did so in May this year, and Merck & Co's Singulair (montelukast) will face generic competition from this month, Fitch Ratings reported recently.

Meantime, new US government figures show that more than 5.2 million enrollees in the Medicare programme have now saved over $3.9 billion on their prescription drug costs as a result of the Affordable Care Act (ACA), which President Barack Obama signed into law in March 2010. 

Also, during the first half of 2012, over one million enrollees in Medicare (the federal healthcare programme for seniors and some disabled people) saved a total of $687 million on prescription drugs when they reached the programme's "doughnut hole" prescription drug coverage gap, giving them an average saving of $629 each this year, say the data, from the Centers for Medicare and Medicaid Services (CSM).

In 2010, Medicare enrollees who hit the doughnut hole received a one-time $250 rebate, which totalled $946 million for the year. Then last year, enrollees began receiving 50% discount on covered brand-name drugs and 7% coverage of generics in the hole, and these discounts totalled over $2.3 billion in savings for 2011. This year, Medicare coverage for generic drugs in the coverage gap has risen to 14%, and this has produced first-half savings for enrollees totalling $687 million, says CMS.

Medicare coverage for both brand-name and generic drugs in the doughnut hole will continue to increase over time until 2020, at which date the coverage gap will be closed, the agency notes.