Disposal practices for unused medications around the world

Abstract

Pharmaceuticals have been detected throughout the environment where at least in some cases, they have been shown to have a detrimental effect. Many result from improper patient disposal of unused pharmaceuticals via environmentally-unfriendly routes, such as the sink, toilet or rubbish bin. This review surveys the current peer-reviewed literature on attitudes and practices to medicine disposal methods as reported by patients and the various medication disposal and destruction systems around the world. A literature search was carried out using the keywords 'medicines disposal', 'unused medicines', 'medicines wastage', and 'medication disposal' in the PubMed TM, ISI Web of Knowledge TM, Google Scholar TM, Medline TM, Scopus TM and International Pharmaceuticals Abstracts TM up to the end of May 2010. Twelve peer-reviewed articles with specified sample sizes were selected. The most popular methods for medication disposal were in the garbage, toilet or sink. Liquid medications were more likely to be rinsed down the sink, as opposed to solid tablets and capsules which were more likely deposited in the rubbish bin. Much confusion exists about the 'proper' way of medication disposal as many countries do not have standard medication disposal protocols. Furthermore, some pharmacies around the world refused to accept unused medications or discouraged the practice. Patients with knowledge about the impact of pharmaceuticals in the environment were more likely to return medications for proper disposal and destruction. It is concluded that it is of paramount importance that a formalized protocol for patient disposal and destruction of pharmaceuticals be implemented around the world.

Introduction

There have been many recent reports of pharmaceutical compounds and their metabolites in the environment (Kasprzyk-Hordern et al., 2008, Snyder, 2008, Kummerer, 2009, Snyder and Benotti, 2010). Pharmaceutical compounds have been detected in surface (Bartlett-Hunt et al., 2009) and drinking (Benotti et al., 2009) water, and even though the concentrations detected are of the order of nanograms to micrograms per liter (Moldovan et al., 2007) there remains an uncertainty about whether compounds at these levels pose a chronic threat to human or animal health (Zuccato et al., 2006). Much research has also been undertaken on the levels of pharmaceuticals in waste water and their possible environmental consequences (Pomati et al., 2006, Lienert et al., 2007, Schmitt-Jansen et al., 2007, Li and Randak, 2009, Parolini et al., 2009, Rosal et al., 2010). However much less is known about the factors that lead to the occurrence of these pharmaceuticals in all these different parts of the environment. Clearly a major factor is the human excretion of these pharmaceuticals and their metabolites into sewage (Heberer et al., 2002) but another significant factor is the human disposal of unwanted medication.

Pharmaceuticals may enter the environment through improper disposal of unused and expired pharmaceutical dosage forms in the toilet or sink (Ruhoy and Daughton, 2007, Comeau et al., 2008). Processes employed in sewage treatment plants are often ineffective in removing all improperly disposed pharmaceuticals and therapeutic medication excreted in unchanged or metabolized forms from effluent before discharge into waterways (Nakada et al., 2006, Kim and Aga, 2007, Zorita et al., 2009) and thus pharmaceuticals can potentially be discharged into waterways. If unwanted pharmaceuticals are disposed of in the garbage, they eventually end up in landfills with the potential to be discharged into the environment as leachate (Barnes et al., 2004).

The use of pharmaceuticals is on the rise, with an estimated increase from 2 billion to 3.9 billion prescription numbers yearly between 1999 and 2009 in the US alone (Kaiser Family Foundation, 2010). Unused and expired medicines often are the result of patients' poor compliance to certain medicines (Lindberg et al., 2008) resulting in many cases is in not taking or finishing courses as directed by the prescriber (Thormodsen et al., 1997, Aziz and Ibrahim, 1999, Ruhoy and Daughton, 2008). Excessive prescribing by doctors (Ekedahl, 2006) may also increase the volume of unused medication. If the likely environmental impact of pharmaceuticals is to be reduced then we must address the issues related to improper disposal practices.

Some of the questions pertaining to the disposal of unused pharmaceuticals by households and individuals include: what are the current methods employed by individuals to dispose of unused and expired pharmaceuticals? Is their choice of disposal methods influenced by any prior knowledge of environmental issues associated with pharmaceuticals? Most importantly, is there a need for a formalized protocol for disposal and destruction of unused and expired medications worldwide in order to minimize their potential impact on the global environment?

In order to evaluate current and past medicine disposal methods by the public around the world, and the impact such methods may have on the environment, it is necessary to establish what are the reported practices and attitudes to medicines disposal. By obtaining this information from the peer-reviewed literature studies, it is possible to infer whether such disposal practices are affected by peoples' demographics and their knowledge of environmental issues concerning pharmaceuticals in the natural environment. This review will also include data on the availability of formalized disposal systems as reported in various countries around the world and deduce their impact on peoples' medication disposal habits.