According to the World Health Organization (WHO), unused medicines are defined as “medicinal products that have not been consumed by the patient, have not passed their expiry date, and have not been returned to a healthcare professional or a take-back program” (1). This definition includes medicines that remain unused by patients for reasons such as discontinuation of treatment, change in medication regimen, or medication surplus. It recommends returning unused medicines to a pharmacy or participating in a take-back program where available. If no take-back programs are available, the WHO suggests disposing of unused medicines in household waste, taking precautions to prevent accidental ingestion or misuse (1). The WHO advises against flushing unused medicines down the toilet or sinks to prevent potential contamination of water sources since medications contain harmful chemicals that may not be effectively removed through standard water treatment processes; hence why they recommend proper disposal methods to reduce environmental risks and protect public health (2, 3).

Globally, the improper disposal of unused medicine poses a danger to public health and environmental safety (4, 5). Different studies suggest that people use different methods for disposing of unused medicines, such as rinsing unwanted medicines down a sink, flushing them down the toilet, throwing them in the trash or garbage, or discarding them in household waste, which were some of the commonest disposal methods commonly practiced, contributing to environmental contamination, particularly in water bodies, soil, and wildlife (5–13). These disposal methods of unused medicines deviate from conventional disposal practices and indicate poor disposal practices (14, 15). This can lead to the presence of pharmaceutical compounds in aquatic ecosystems, causing harm to aquatic life and the environment and potentially entering the human food chain (15, 16). For example, studies have shown that trace amounts of pharmaceutical compounds found in water sources can disrupt the hormonal systems of aquatic species, including fish, leading to long-term ecological consequences (17). Additionally, improper disposal may result in the contamination of drinking water sources, posing significant risks to human health, such as the development of antibiotic resistance and exposure to harmful chemicals (18).

Improper disposal practices can vary across countries and communities, influenced by factors such as cultural norms, lack of awareness, and limited access to proper disposal facilities. Determining the specific factors or determinants that contribute to the accumulation of unused medicines can vary across contexts and populations. However, patient behavior and belief, prescription practice, medication adherence, availability of take-back programs, environmental concerns, and awareness were the common determinants of unused medicines in previous literatures (19–23). Moreover, studies suggest that individuals with lower educational status and limited access to health information are more likely to engage in poor disposal practices. Chronic diseases, which often result in the accumulation of unused medications, further exacerbate this issue, especially when patients lack clear guidance on how to dispose of their medications safely (20–23).

Given the increasing use of pharmaceuticals globally, it is essential to understand the determinants of poor disposal practices and develop tailored interventions. In countries like Ethiopia, where public awareness about pharmaceutical waste management is low, these practices are even more prevalent. There is limited research available on the disposal practices and determinants of unused medicines among the general public in Gondar City. This gap hinders the development of effective strategies to mitigate the risks associated with improper disposal and ensure safe medication management. Targeted educational programs and policy interventions, particularly in low- and middle-income countries, are necessary to mitigate the environmental impact and improve public health outcomes.

Therefore, this study aimed to assess the disposal practices of unused medicines and determinant factors among the general public in Gondar City. The findings of this study will not only contribute to the limited literature on disposal practices in Gondar City but will also provide valuable information for policymakers, healthcare providers, and relevant stakeholders to make targeted interventions that can be designed to improve public awareness, accessibility to proper disposal facilities, and regulatory frameworks.

The present study assessed disposal practice and determinants of unused medicines among the general public in Gondar city. The findings of this study revealed that 56.9% of the study participants had poor disposal practices, from a total of eight-hundred forty-five study participants with 93% response rate. These results suggested that a significant proportion of the population in Gondar City do not properly dispose of their unused medicines.

In this study, the proportion of respondents who have a good disposal practice (43.1%) is lower as compared to a study conducted in Northern Nigeria, which is 60.2% (27), in Tanzania (96.0%) (29), in Kenya (28), in Iraq (70%), in Jordan (58.1%) (31) and in Pokhara (Western Nepal) showing 50% of the study participants practicing proper drug disposal (24). This study finding also aligns with results from similar studies across various regions. For example, a study in Turkey and Northern Nigeria also revealed poor practices, where 81 and 60.2% of the study participants disposed by throwing them in the garbage, indicating widespread improper disposal behaviors for unused and expired medications (30, 31). Moreover, another systematic review found that urban households, particularly in Asia and Africa, demonstrated significant storage and wastage of medicines, with improper disposal being a common issue across regions (32). The variation in the prevalence of poor disposal practices for unused medicines across different studies and countries can be attributed to several factors. First, differences in healthcare systems and regulations might be the reason that countries with well-established healthcare systems and clear regulations on pharmaceutical disposal tend to have lower rates of improper disposal. For instance, high-income countries often have formalized take-back programs or designated drop-off locations for unused medicines, while lower-income countries may lack such infrastructure (32). In addition, public knowledge and awareness about proper medicine disposal significantly influence behavior. Differences in literacy levels and public health education programs play a crucial role. Moreover, regarding accessibility to proper disposal facilities and socioeconomic factors, higher-income countries tend to have more resources for waste management, public health infrastructure, and environmental regulations. In contrast, in low- and middle-income countries, poor waste management systems and fewer regulations may contribute to higher rates of improper disposal of medicines (32). The improper disposal of unused medications can have significant implications for public health, including contributing to drug pollution and the development of antibiotic-resistant bacteria. When medications are disposed of inappropriately, either by flushing them down the toilet or throwing them in the regular trash, they can end up in the water supply or soil, leading to contamination and potential harm to human health. One major concern is the impact of pharmaceutical pollution on the environment, as it can contribute to the development of antibiotic-resistant bacteria and the spread of drug resistance in the community. A study by Larsson et al. highlighted the link between pharmaceutical pollution and the development of antibiotic resistance (33). Improper disposal of antibiotics, in particular, can lead to the release of active drug compounds into the environment, providing a selection pressure for bacteria to develop resistance. This can have serious implications for the effectiveness of antibiotics in treating bacterial infections and can pose a significant threat to public health (33).

In Gondar City, like many urban areas, pharmaceutical contamination in the environment is a growing concern due to various factors, including the limited technologies for pharmaceutical removal in wastewater treatment plants. Research shows that pharmaceutical residues are present in water bodies due to the limited effectiveness of conventional wastewater treatment processes in eliminating these compounds. Studies, such as one conducted in Spain, have detected pharmaceutical residues in treated wastewater effluents, indicating the need for more efficient removal methods (34). Similarly, research by Kasprzyk-Hordern et al. (35) in the UK underlines the importance of advanced treatment technologies like ozonation and activated carbon filtration to prevent the release of pharmaceutical compounds into the environment from wastewater effluents (36–38).

The current study revealed that the most common method of disposing of unused medicines was tossing them in the dustbin, followed by dumping them in sanitary landfills and flushing them down the toilet. This disposal practice was consistent with similar studies conducted in Malaysia (39–41). In contrast, studies in the United States, Canada, the United Kingdom, and Australia (42–44) showed a preference for take-back programs organized by pharmacies, healthcare facilities, or local governments for medication disposal. Interestingly, findings from Ghana and Afghanistan diverged from this study results, as burying unused medicines in the ground and storing them at home until they expired were identified as the predominant disposal practices in these countries, respectively (22, 45). These differing practices may be attributed to variations in awareness levels, laws and regulations regarding medication disposal practice, infrastructure availability, attitudes toward medication disposal, prevalent health conditions, and the effectiveness of local pharmacists, healthcare providers, and health offices in promoting safe disposal practices.

In the current study, factors such as lower educational status, having a chronic disease, and poor knowledge toward disposal practices were identified as being significantly associated with the poor disposal practices of unused medicines.

Based on our study, study participants who cannot read and write (AOR = 2.76, 95% CI: 1.59, 4.79) were 2.76 times more likely to have a poor disposal practice compared with individuals who had completed primary school, secondary school, or college and above. This finding aligns with previous research conducted in various countries, which has shown that higher education levels are often associated with better health-related practices, including medication disposal (46, 47). This is consistent with research from Egypt, Pakistan, and India, which highlighted that individuals with lower levels of education are less likely to understand and practice proper disposal methods (32, 48). It is hardly surprising that improved health practices, such as disposing of medications properly, are frequently linked with higher education levels. Higher-educated people may be more aware of their surroundings and more perceptive about information, but lower-educated people are more prone to encountering issues and may not be aware of the negative consequences of improper medicine disposal. While higher education levels may be associated with better knowledge of proper medication disposal methods, it is essential to consider that education alone does not determine an individual’s behavior in this regard. Factors such as awareness, access to information, and personal beliefs also influence how people choose to dispose of their medications. Moreover, the lack of awareness about existing laws and medication disposal programs presents a significant challenge that requires attention and resolution. In Ethiopia, there are waste management directives for medicine disposal that incorporate a drug take-back program (49). Despite the existence of these directives, there has been limited initiative to enhance public awareness regarding the safe disposal of unused medicines and allocate budgets to facilitate the disposal of unused medicines.

Poor knowledge (AOR = 1.07, 95% CI: 0.77, 1.49) is another significant factor in this study. Respondents with poor knowledge about how to dispose of unused drugs were 1.07 times more likely to dispose of pharmaceuticals improperly. This is supported by a study that found those with poor knowledge were 4.8 times more likely to improperly dispose of unused medications (50). Furthermore, in research conducted in Arba Minch (51), 82 % of the respondents said they had no prior information about how to properly dispose of medications, and the majority of respondents (n = 208; 59.7%) said that medications that were unused or expired were considered waste. In addition, a study conducted in Qatar and Southwest Ethiopia showed the majority of the households lack knowledge on safe disposal methods, and most disposal methods used by households are not recommended (52). Education plays a key role in developing the importance of medicines and treatment regimens, rational utilization of healthcare services, proper disposal methods and an understanding of the needs and demands of pharmaceutical care. Furthermore, knowledge also maximizes the opportunity to exercise better control over the appropriate disposal of drugs, treatment plans, medical problems, treatment regimens, and disease conditions.

Having chronic diseases was found to be significantly associated with poor disposal practices of unused medicines. Studies show that individuals with ongoing health conditions tend to accumulate more medicines, leading to increased waste and improper disposal (30, 32). This finding is corroborated by studies in countries like Brazil, where people with chronic conditions tend to accumulate unused medicines due to frequent prescriptions but often lack clear instructions on safe disposal. In the U.S.A., medicines used for chronic diseases such as hypertension, diabetes, nervous system, gastrointestinal disease, cholesterol and heart disease, pain, and mental health problems are commonly reported unused medicines, indicating that many patients with chronic diseases keep leftover medications, unaware of the risks associated with improper disposal (53). Contrary to what we found, respondents who took acute-sickness medications were more likely to discard any unused or leftover medication in a way that could be dangerous in Malaysia (41) and Arba Minch (51). This is because the duration of therapy for acute illnesses is often brief, and it is anticipated that patients will cease taking their prescription if their health improves. This leads to a rise in production as well as the unsafe disposal of unused medication. A possible explanation for the variance in chronic patients might be the current higher and rising prevalence of chronic health conditions and excessive pharmaceutical intake. A systematic review of observational studies across Ethiopia found that acute poisoning cases are more prevalent among individuals under 30 years of age, with a higher incidence in females. The substances frequently involved include organophosphates, household cleaning agents, and pharmaceuticals. The case fatality rate varies, with some studies reporting rates up to 14.8% (54). Farmers (18.8%), unemployed individuals (18.2%), students (54.3%) and daily laborers (13%) were identified as the predominant victims for the drug poisoning. Other groups were house wives, daily laborers, waitress, government employee, merchant, and prisoner (55, 56). Education level of the victims was reported were Illiterate (59.2%), primary school (21.4%), secondary school (16.5%), and higher institute (2.9%) level personnel (57). In relation with this, the prevalence of self-medication practice has persisted in both developing and developed countries. In previous studies in Gondar, the prevalence of self-medication practice was 50.2% in 2019 (58) and 79.2% in 2021 (59) and, more than 60% (60.9%) of the households had a history of self-medication practice within their family members in the town (58) which will influence the consumption and of disposal practice of medications. In addition to this self-medication habit, the COVID-19 pandemic has significantly influenced medication consumption and disposal practices worldwide, including in Ethiopia. During the pandemic, the public in Ethiopia exhibited a rise in self-medication habits as individuals sought to prevent or manage COVID-19 symptoms. People self-medicating, writing their own prescriptions, and improperly managing their medications have become more common, and lockdowns and restricted access to doctors have been related to this trend (60, 61). A study in Ethiopia found that medications such as antibiotics, vitamins (e.g., vitamins C and D), and traditional remedies were frequently used without proper medical consultation (62, 63). This increase in medication consumption could lead to a higher likelihood of unused medications in households and improper disposal.

The current study’s findings revealed poor disposal practices of unused medicines in a significant proportion of the study participants. Low educational status, the presence of chronic diseases, and poor knowledge toward disposal practices were identified as significant determinants of poor disposal practices of unused medicines. Therefore, encouraging interventions include the implementation of educational programs that focus on safe disposal practices of unused medicines, considering individuals with chronic diseases and other target individuals with lower educational levels, emphasizing the importance of proper disposal and the potential risks, and providing reminders, and clear instructions on how to dispose of medicines safely, taking into account any specific considerations related to chronic conditions. Conducting further research to explore the cultural and contextual factors influencing disposal practices of unused medicines will also be very important. The stakeholders should also focus on the aforementioned factors to design appropriate intervention strategies.