Now, West African leaders are meeting in Lome to sign an agreement aiming to crack down on the trade.
Congo, Niger, Senegal, Togo, Uganda, Ghana and The Gambia will discuss measures to clamp down on trafficking in fake medicines, says the Brazzaville Foundation.
But how big a problem is counterfeit medicine in Africa, and what impact does it have?
How many counterfeit drugs are there?Globally, the trade in counterfeit pharmaceuticals is worth up to $200bn (£150bn) annually, with Africa among the regions most affected, according to industry estimates.
The World Health Organization (WHO) says 42% of all fake medicines reported to them between 2013 and 2017 were from Africa .
The European region and the Americas (North and South) accounted for 21% each.
But how reliable are these figures?
The WHO has a reporting mechanism that relies on national or regional regulatory authorities around the world to notify it of seizures. So the data for 2013-17 is only as good as the surveillance and reporting systems in the countries or regions concerned.
Analysis by the London School of Hygiene and Tropical Medicine for the WHO estimates substandard and fake anti-malarial drugs could be causing 116,000 extra deaths from the disease every year in sub-Saharan Africa at a cost to patients and health systems of on average $38.5m a year.
And in 2015, a study published in the American Society of Tropical Medicine and Hygiene estimated more than 122,000 children under the age of five died each year because of sub-standard anti-malarial drugs in sub-Saharan Africa .ough these results are only estimates, the scientists say they suggest poor quality drugs are important contributors to under-five mortality rates.
Why is it hard to fight fake medicines?
Fake medicine can often be indistinguishable from the real products, with the packaging as good if not better than the original.
And weak or inconsistent legal frameworks and the lack of regulations to address sales, often carried out online or in informal locations, add to the problem, the UN says.
There’s also an issue with the cost of drugs in poorer countries.
“If a good quality medicine from a known supplier is too expensive, people may try a cheaper one from an unlicensed supplier,” the WHO says.
