Blog | Wednesday, October 10, 2012

QD: News Every Day--Drug shelf life can extend for decades

Common drugs may remain viable for use years after their expiration date, a study found.

Researchers scoured the shelves of a retail pharmacy for unopened packages of pills that had been there, in some cases 28 to 40 years. They came up with 8 packages with 15 active ingredients, and then tested for the active compounds.

Results appeared in a research letter in Archives of Internal Medicine.

One ingredient had no appropriate test, and of the remaining ones, 12 met the 90% concentration considered as acceptable potency. Three compounds had potency at 110% of the labeled content. Amphetamine and aspirin were present at less than 90%.

Fiorinal's ingredients of butalbital, aspirin, caffeine, and codeine phosphate had almost 100% of labeled concentrations, while Codempiral No. 3's ingredients of phenacetin with codeine phosphate were all less than 95%, suggesting the packaging was less intact, the researchers wrote.

The FDA does not require drugmakers to determine how long medications remain potent; the expiration dates are set by the companies, researchers noted.

They also cited the federal government's Shelf-Life Extension Program, which tests government stockpiles of drugs and found that 88% of 122 drugs stored under ideal conditions had their expiration dates extended more than one year, with an average extension of 66 months and the furthest of 278 months. Each dollar the government spends proving shelf life saves $13 to $94 on buying newer product.

In comparison to what researchers found on the retail pharmacy's shelves, 12 of 14 drugs lasted 336 months and 8 lasted 480 months.

"Given that Americans currently spend more than $300 billion annually on prescription medications, extending drug expiration dates could yield enormous health care expenditure savings," the researchers concluded.