US Pharm. 2008;33(6): HS-20-HS-24.

At some point, certain medications become unused and unwanted, whether due to expiration, noncompliance, change in therapy, or other reasons. If not disposed of properly, these medications may harm society and the environment. This article discusses these risks, reviews the laws and regulations governing the collection and disposal of unwanted medications, and offers suggestions about what pharmacists can do to reduce the burden of this widespread problem.

Scope of the Problem
Close to 5,000 tons of pharmaceuticals and personal-care products (PPCPs) are discarded annually in the United States.1 This group comprises human- and veterinary-use chemicals, including not only prescription compounds but also diagnostic agents, nutraceuticals, fragrances, and many others. Tracking the exact amount involved is difficult due to the small quantities of products disposed of by households and small businesses. Additionally, there are potentially huge stockpiles of old, unused PPCPs in the homes of patients who are reluctant to throw out medicines that are difficult and expensive to obtain.

A 2004 study surveyed pharmacies and patients about unwanted PPCPs.2 Of the 100 pharmacies, 97% had a policy on how to deal with their expired undispensed medications, but only 5% had consistent recommendations for how patients should dispose of their medications. More than half of patients disposed of unwanted medications in the trash, and about one-third flushed them down the toilet; only 1% returned them to the pharmacy. A more organized approach to handling unwanted medications is needed.

Nursing homes are a significant source of waste PPCPs. A 2003 survey in Washington State estimated that each nursing home generates 8 lb of unpackaged waste medications each year.3 Given that there are more than 18,000 nursing homes in the U.S., more than 70 tons of waste medications could be generated annually from this source alone.4 Data are not available regarding medication waste generated by group homes and assisted-living facilities, but these sites probably are also major contributors.

Risks to Society
Unused medications offer many risks to society. Of obvious concern is the risk of accidental poisoning, which is estimated to be the second leading cause of accidental death in the U.S.5 Pain-relief medications are the most common poisoning agent among adults and rank number three behind cosmetics and household cleaning products in children under the age of 6.5 National poisoning rates are alarming among young children, with four million accidental-poisoning events occurring annually.5

The presence of unused medications in the home presents opportunities for diversion by those seeking to use medications recreationally. The percentage of teens who abuse prescription drugs has been creeping steadily higher. The percentage increase of adults abusing prescription opioids from 1992 to 2003 was 81%; among teens aged 13 to 18 years, the rate of increase during this period was a staggering 542%.6 Prescription psychotropic medications are the fourth most commonly abused drug among U.S. teens.6 Obviously, any reasonable action to keep these medications from being diverted should be taken.

Risks to the Environment: Priority Pollutants
In 1977, a total of 126 chemicals were defined as "priority pollutants" by the federal Clean Water Act (CWA).7,8 The CWA does not cover many other toxic chemicals being released into the water, however. Decisions to expand the list must consider the toxicity, persistence, and degradability of the pollutant; the potential presence and importance of organisms in any waters affected; and the nature and extent of the effect of the toxic pollutant on such organisms. Since 1977, a small number of revisions to the list have been made by the administrator of the U.S. Environmental Protection Agency (EPA).

Priority pollutants are subject to several different kinds of regulatory activity, some based on considerations of water quality and others based on technologies available for pollution control in different industrial sectors. The EPA establishes criteria for the quality of ambient water (e.g., lakes and streams) that identify concentration levels of specific chemicals that will not pose unacceptable risks to human or aquatic life. These criteria are not legally enforceable, but they can serve as the scientific foundation of enforceable water-quality standards set by individual states. Separately, the EPA also sets limits on the discharge of priority pollutants (called effluent limits ) by various types of industries. These limits are generally based on the "best available technology economically achievable" for controlling discharges. Such technology may or may not succeed in keeping discharges below levels that adversely affect water quality.

Although priority pollutants and their impact on the environment have been a major focus in the last three decades, a much larger group of chemicals, including PPCPs, has received little attention.

Pharmaceuticals in the Environment
Water: It is hard to control the amount of pharmaceuticals entering the environment.9 Traces of pharmaceuticals and their metabolites have been detected in waste­ water; sewage-treatment plants are a major source of their release. Wastewater treatment plants are designed primarily for the removal and treatment of human excrement, not substances like PPCPs. As a result, some PPCPs pass through the wastewater treatment facility altered or unaltered and then enter lakes, rivers, and streams.

Another route by which pharmaceuticals enter the water supply is through improper disposal of unused and expired medications. In a study of 301 patients, more than 35% believed that it was acceptable to flush medications down the toilet, and 21% thought it was fine to put them down the sink.10

In a 2002 study by the U.S. Geological Survey, 80% of 139 streams sampled tested positive for PPCPs.11 Numerous medications have been found in trace amounts in groundwater, surface bodies of water, and drinking water. The presence of pharmaceuticals and their metabolites in water recently has been recognized as potentially dangerous. Usually, the concentration of these medications is negligible; long-term exposure to even low levels of multiple medications could be hazardous, however.

According to studies, the PPCP-transformation process varies among sewage-treatment plants depending upon sewage characteristics, weather conditions, and the design and operation of treatment processes. Upon release of treated sewage into a receiving water body, residual PPCPs may be diluted and blended with contaminants from other release points, as well as runoff and sewage. Conventional processes for treating drinking water for PPCPs have been shown to be ineffective.11 Other methods, including oxidation with chlorine and ozone and activated carbon and membrane filtration, can effectively remove antibiotics and some other pharmaceuticals.8

Aquatic Organisms: Some compounds found in rivers and streams are potentially harmful to aquatic organisms, affecting their reproduction and development even at low concentrations.12 Even negligible amounts of estrogen can have a feminizing effect on male fish, thereby potentially decreasing the reproductive ability of affected species.8,12 Additionally, medications that affect serotonin, norepinephrine, and dopamine have been shown to alter the spawning of shellfish and delay development in fish and frogs.8,12 The greatest current concern regarding pharmaceuticals in the environment is their potential effect on small aquatic organisms, primarily because these organisms have quick generation times, which means that multiple generations are easily exposed.12 As a result, there is a greater chance that the effects will not be limited to individual organisms but instead will accumulate over time to cause population-wide effects.12

Regulations
Definitive, consistent guidance is lacking regarding proper disposal of medications by the public.13 It is illegal in many states to give away any drug that was obtained by prescription. Due to quality-assurance issues, it also is illegal in many states for pharmacies to accept returned unused medications. For these reasons, the FDA has set no general policy governing reuse and has instructed that each state set its own policy. The FDA doesn't prohibit reuse, but it emphasizes the hazards and pitfalls that require vigilance when a reuse program is being created.

Pharmacists and other health care professionals are prohibited by the Controlled Substances Act (CSA) from accepting controlled medications (Schedule I–V) from household consumers for return.14 The CSA states that only law-enforcement personnel may receive controlled substances from household consumers (the CSA considers nursing homes to be households).14 It is illegal for a pharmacist or pharmacy to accept medications from patients without first verifying that no controlled substances are included.14 Neither can a pharmaceutical take-back provider (also known as a reverse distributor) accept medications from patients, as the medications are considered to be household waste, which take-back providers are not licensed to handle.14 The Drug Enforcement Agency may grant waivers from the CSA regulations in specific instances, but this is rarely done.14

Disposal Options
A handful of options are available to consumers wishing to properly dispose of unwanted PPCPs. Many counties nationwide have Household Hazardous Waste (HHW) facilities where consumers can safely dispose of hazardous materials. Some HHW sites may not accept PPCPs if they lack the experience, training, or necessary security to handle them. Law-enforcement offices can legally accept waste PPCPs, including controlled substances, but they may have insufficient manpower or storage space.

Some organizations have issued guidelines about how the public can safely dispose of unwanted medications. 15 They suggest that medications be removed from their containers and mixed with household waste such as coffee grounds or used kitty litter.15 The FDA has recommended that certain unwanted medications be flushed down the toilet (TABLE 1), primarily due to their high abuse potential.15 While these practices may reduce the chances of drug diversion, they still may add to the environmental impact of unwanted PPCPs.




Other, more innovative techniques have been implemented. In one case, a cooperative health system in Seattle participated in a medication-disposal program.16 This program allows consumers to take expired and unwanted medications to participating pharmacies and drop them into protected steel bins. The bins are under the pharmacist's observation, but the pharmacy staff cannot access the contents. When the bins are full, they are transported to incineration sites, where the contents are safely destroyed. Programs such as this could reduce the amount of medications infiltrating wastewater and landfills.

One school of pharmacy participated in an unwanted-medication collection program developed by the county's recycling program. For one day, various sites were designated as drop-off points where people could leave their unwanted medications. Law-enforcement officers at each site ensured compliance with CSA regulations and kept the area secure. Pharmacists and pharmacy students were on hand to answer questions. The collaboration with law-enforcement officials allowed for the collection of all medications, including controlled substances. In six hours, the sites collected twenty-two 10-lb boxes of medications, which were then incinerated at a facility licensed to destroy biomedical waste.

Conclusions
Due to increased publicity about "green" efforts, the general public has become much more aware of environmental issues; however, there does not seem to be a corresponding emphasis on the safe disposal of PPCPs, which would reduce their environmental impact and decrease the potential for accidental poisoning and recreational drug use. Pharmacists, due to their accessibility, can play a greater role in educating the public about the hazards of improper PPCP disposal as well as the importance of medication compliance. The pharmacist is well suited to instruct patients about the use and misuse of medications and perhaps personal-care products. The presence of PPCPs in the environment is a problem that will continue to grow as the population expands and more medications are dispensed. It makes sense to reduce the contamination, poisonings, and abuse potential associated with PPCPs as much as possible. The proper disposal of used and expired medications is one area in which a notable difference can be made.

REFERENCES
1. Illinois-Indiana Sea Grant. The Helm. Pharmwaste: a prescription for troubled waters. http://web.extension.uiuc.edu/helm/. Accessed February 10, 2008.

2. Boehringer SK. What's the best way to dispose of medications? Pharmacist's Letter/Prescriber's Letter . April 2004;200415.

3. Oliver D, Chapman AI. Pharmaceutical Waste Survey. Seattle, WA: Local Hazardous Waste Management Program, King County; April 2003. Publication number SQG-RR-6. www.govlink.org/hazwaste/publications/pharmaceuticalwastesurvey.pdf. Accessed April 15, 2008.

4. National Center for Health Statistics. Nursing home care. www.cdc.gov/nchs/fastats/nursingh.htm. Accessed February 15, 2008.

5. Kaufman MM, Smolinske S, Keswick D. Assessing poisoning risks of household hazardous materials: using focus groups to improve a survey questionnaire. Environ Health. 2005;4:16.

6. Manchikanti L. National drug control policy and prescription drug abuse: facts and fallacies. Pain Physician. 2007;10:399-424.

7. Texas A&M University Department of Geology & Geophysics. Environmental Geochemistry. Priority pollutant list. http://geoweb.tamu.edu/courses/geol641/docs/02PriorityPollutantList. Accessed February 1, 2008.

8. Daughton CG, Ternes TA. Pharmaceuticals and personal care products in the environment: agents of subtle change? Environ Health Perspect. 1999;107(suppl 6):907-938.

9. Musson SE, Townsend T, Seaburg K, Mousa J. A continuous collection system for household pharmaceutical wastes: a pilot project. J Air Waste Manag Assoc. 2007;57:828-835.

10. Seehusen DA, Edwards J. Patient practices and beliefs concerning disposal of medications. J Am Board Fam Med. 2006;19:542-547.

11. Pharmaceuticals from Households: a Return Mechanism (PH:ARM) Pilot Team. Disposal of Medications from Residential Consumers: Issues, Barriers, and Opportunities. Seattle, WA: Local Hazardous Waste Management Program, King County; October 12, 2005. www.govlink.org/hazwaste/publications/UnwantedMedicationsPrimerFinal.pdf. Accessed April 18, 2008.

12. Illinois-Indiana Sea Grant. Habitats and Ecosystems. Disposal of unwanted medicines: a resource for action in your community. Introduction. www.iisgcp.org/unwantedmeds/updatedToolKitMaterials/1.0Introduction.pdf. Accessed February 1, 2008.

13. Daughton CG. Cradle-to-cradle stewardship of drugs for minimizing their environmental disposition while promoting human health. II. Drug disposal, waste reduction, and future directions. Environ Health Perspect. 2003;111:775-785.

14. DEA Diversion Control Program. Questions & answers. www.deadiversion.usdoj.gov/faq/general.htm#pre_med. Accessed February 15, 2008.

15. Illinois Poison Center. Recommendations for disposal of unwanted or expired medication. www.mchc.org/ipc/AboutIPC/News/IPC%202007%20medicine%20disposal.pdf. Accessed February 28, 2008.

16. Saving the environment one prescription at a time: members devise a unique, safe disposal system for consumers. InterSections. 2007:11-12.

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