A study published in the Archives of Internal Medicine claims off-label use of drugs is more frequently grounded in observation and anecdote than hard science.
The study's data, from a national survey of 3,500 office-based physicians, determined that 21% of the 725 million prescriptions written in 2001 were for off-label uses, with 73% of those off-label scripts containing little or no scientific justification or no discernable evidence, the study said.
Funded by the federal Agency for Healthcare Research and Quality, the study compared patient diagnoses with labeling information from the 100 of the most commonly prescribed drugs and 60 random medications and assessed the amount of scientific support for each case of off-label use. Some were clear extensions of the drug's use while others were not, the authors said.
The lack of substantial safety and effectiveness information in some off-label prescribing could put consumers at risk of taking ineffective or potentially harmful medications, the authors added.
"Efforts should be made to scrutinize underevaluated off-label prescribing that compromises patient safety or represents wasteful medication use," they wrote.