I think it is not good practice to take risk with health related issues.  May be some medicine will work even after the expiry date, but there may be some risk related to it that it may have some adverse effect after the expiry date.

In my view, giving expiry dates in medicines and certain other products are one of the business tricks of the manufacturers  to increase their sale in the market. If there is no expiry date, the customers store and use that products for long days. If the product is with expiry date, people normally throw away that product after the expiry date and spend money to buy a new one. If the sale of a product is very high in the market, the producers make more such products. This is the way to increase their income. 

Printing Expiry date on Medicines and food packets like packed chips, Pulihora, a preparation made in most of the Southern states etc is already in practice. You can see the labels on food packets,

Every thing has some useful life. Medicines also cannot be used for an indefinite period. Expiry date is a guide. Even if medicines are okay after expiry date, it is better not to risk by using the medicines 

I do agree. When it comes to Health and safety, even though the power of medicines is in tact, the user should not use for his own good.

Every product has to have a limited shelf life and when it comes to medicine as well as packaged food items then it is always fair not to take any risk. Gambling with life is not at all an intelligent choice.

Expiry date on Medicines and packaged foods are mandatory. But sadly, consumers are not aware of the importance of Expiry dates, even in Urban areas. What all they want is the product.