Do you store your medications in your medicine cabinet for long periods of time? If so, keep just your weekly dose of meds there to prevent humidity from the shower or bath from ruining them. Keep them in a dry location for longer storage, such as in a drawer, closet, or pantry not located in the bathroom.
If meds go unused or expire, go to disposemymeds.org, an online resource to help you to find medication disposal programs at the local independent community pharmacy near you. Or, secure them in a plastic bag with coffee grounds (to prevent children and pets from getting into them) and throw them away.