Drug dumping occurs when large amounts of unwanted and unusable pharmaceutical products are sent from developed countries to areas of crisis. This usually occurs after a humanitarian disaster such as an earthquake, flood or war.
Sometimes the drugs come from individuals emptying their first aid cabinet which are then distributed by well meaning charities.
An impulse that is understandable but not very helpful if you are on the receiving end. But more often large scale drug dumping comes from donations made to charities from pharmaceutical companies.