Final answer:
Expired medications should be removed from active stock and properly disposed of according to local regulations to prevent potential harm and environmental pollution. Flushing medications is not a recommended disposal method.
Step-by-step explanation:
The correct procedure upon discovering that the expiration date has been exceeded on medication is to remove from active stock for proper disposal. Medications that are past their expiration date may not be effective or could be potentially harmful, so it's vital to ensure they are not used. The disposal should be done according to local regulations and guidelines to prevent environmental pollution, which is a known risk with improper disposal methods, such as flushing medication down the toilet or sink.
In the US, the disposal is typically handled through voluntary initiatives at a local level, while European countries may have structured take-back systems. Despite these available systems, investigations in Germany have highlighted that a significant percentage of people dispose of liquid pharmaceuticals and tablets via the toilet or sink, which is not recommended.