RESUMO
Unused, damaged, and expired medicines (UEMs) pose disposal challenges globally, despite their importance. The environmental disposal of UEMs portends public health consequences, hence, this study in high-density (HDS) and low-density (LDS) urban households in Southwest Nigeria. The comparative, cross-sectional study utilised multi-stage samplingto enrol 404 females, experienced in use and medicines safekeeping. The response rate was 93%. Data were analysed by IBM-SPSS, version 20. Continuous and categorical variableswere presentedin tables as mean(±SD), proportions (%), respectively while χ2 and logistic regression statistics determined differences between LDS and HDS (Pα > 0.05). 53.4% and 71.2% of respondents respectively had good knowledge and positive attitudes to safe disposal of UEMs. At least 31.5% of households don't stock medicines while antimalarial (57.3%), analgesics (52.7%) and antibiotics (49.7%) predominate in households and significantly different between LDS and HDS. 72.9% and 67.8%; 47.9% and 55.6% respondents in LDS and HDS, respectively, disposed of solid and liquid UEMs in storage bins, though 34.9% (LDS) and 16.7% (HDS) disposed of liquid UEMs in toilet/sink. There were significant differences in medicines abundance and disposal practices between LDS and HDS for solid and liquid medicines. 37.1% of respondents perceived consequences for the poor UEMs disposal, including accidental ingestion (76.6% vs 26.7%), land pollution (69.6% vs 36.7%), water pollution (72.4% vs 32.8%) and toxicity (58.3% vs 32.8%), respectively in LDS and HDS. Respondents' good knowledge and positive attitudes contrasted with poor UEMs disposal practices, which compromise public health. Legislation, compliance monitoring and enforcement are germane for incentive-driven UEMs recovery.