In this age of increasing antibiotic resistance, one easy way that everyone can help to tackle resistance, and also protect our environment, is to minimise the amount of drugs that get put into landfill or that enter the waterways. The best way to dispose of unwanted medicines is to return them to any local pharmacy for collection under the free Return Unwanted Medicines program. http://www.returnmed.com.au/
Medicines disposed of in landfill or down the drain or toilet in the home have been shown to affect animal and plant life and even been detected in the drinking water supply.1
Every little bit helps and so safely disposing of your unwanted medicines, by taking them to your local pharmacy, will go a long way.
Stackelberg PE, Furlong ET, Meyer MT, Zaugg SD, Henderson AK, Reissman DB. Persistence of pharmaceutical compounds and other organic wastewater contaminants in a conventional drinking-water-treatment plant. Sci Total Environ. 2004 Aug 15;329(1-3):99-113.