Mixing any unused or expired over-the-counter and/or prescription medications with used coffee grounds can make the discarded drugs less appealing to children, pets, and people who may rummage through your trash.
If you’re not a coffee drinker who has grounds readily available, you can ask a local coffee shop for used grounds or find another undesirable substance such as kitty litter. The U.S. Food and Drug Administration recommends this method if the drug label does not give specific disposal instructions and you don’t have a medication take-back program in your area. To find out if a local program exists, contact your household trash and recycling service.
Once you’ve mixed the medications with the grounds or litter, put the contents in a seal-able bag, empty can, or another container to help prevent medication leakage from the garbage bag.
Before throwing away any bottles for prescribed medications, scratch out all identifying information on the label. This will help to protect your identity and personal health information.
Source: U.S. Food and Drug Administration