May 18, 2012 -- Prescription medication "take-back" programs are increasingly promoted as a way to safely dispose of unused drugs, but they are no better for the environment than simply throwing old drugs in the trash, a new study suggests.
When researchers used a complicated methodology called "comparative life cycle assessment" to estimate the environmental impact of flushing, incinerating, and trashing old medications, they found little difference between burning the drugs -- which is what most take-back programs do -- and having them end up in the landfill.
Close to 200 million pounds of drugs go unused in the U.S. each year.
There are serious concerns that antibiotic and hormone medications pose a threat to the nation's lakes, rivers, and other water supplies.
While most of these concerns involve flushed waste that contains residues of used medications, unused drugs may also be finding their way into the nation's water supply, researcher Steven J. Skerlos, PhD, tells WebMD.
FDA Says Trash Some Unused Drugs
Take-back initiatives typically involve the collection of unused drugs by participating pharmacies for incineration with other medical wastes.
Skerlos, an associate professor of mechanical engineering at the University of Michigan, says these programs may actually be worse for the environment than throwing drugs in the trash due to the greenhouse gases produced by transporting and burning the medications.
If there are no disposal instructions given on the drug label or patient information sheet, the FDA recommends throwing away some prescriptions by:
- First mixing them with an unpalatable substance such as kitty litter or used coffee grounds,
- Placing the mixture in a container such as a sealed plastic bag,
- And disposing of the bag with other household wastes.
However, there is one big exception to this recommendation, FDA spokesperson Morgan Liscinsky tells WebMD.
Dangerous Drugs Should Be Flushed
Medications that are especially harmful and could potentially be deadly if taken accidentally should not be put in the trash.
Instead, they should be flushed down the toilet or sink to eliminate any chance that a child or pet will find them, the FDA says.
These drugs include powerful pain relievers and other drugs that are widely abused like methadone, morphine, OxyContin, and Percocet.
Of special concern are powerful narcotics delivered by patch, such as the drug fentanyl.
"Even after a patch is used, a lot of the drug remains in the patch, so you wouldn't want to throw something in the trash that contains a powerful and potentially dangerous narcotic that could harm others," FDA senior program manager Jim Hunter, RPh, noted on the agency's web site.
A complete list of the drugs recommended for flushing by FDA can be found on the agency's web site in the consumer section entitled "How to Dispose of Unused Medicines."
Drug Disposal Safety Questions Remain
While environmental concerns remain about the impact of flushing any drugs, the FDA notes that there is as yet no solid evidence linking flushing to specific risks in humans.
And scientists with the Environmental Protection Agency (EPA) have not yet found evidence of adverse effects on human health associated with drug residues in the environment.
Skerlos says that since more than half of people in the U.S. already throw their unused drugs in the trash, asking them to take part in drug take-back programs could have significant downsides, including increased inconvenience, longer drug storage in the home, and higher costs to society.
Skerlos and colleagues estimate that a nationwide drug take-back program would cost $2 billion a year.
They write that re-evaluation of drug disposal options may become necessary as our understanding of the environmental impact of these options increases.
The study appears online in the American Chemical Society journal Environmental Science & Technology.