Antimaláricos falsificados: ¿cuál es la magnitud del problema?

Fake Antimalarials: How Big is the Problem?


[This blog is part of the #DefeatMalaria World Malaria Day blog series hosted by Roll Back Malaria, to be published between April 8 and May 1, 2015]

In recent years, it has been reported that up to one third of antimalarials are fake. To understand the scale of this problem, the Artemisinin-based Combination Therapy (ACT) Consortium carried out a large drug quality programme over five years, analysing more than 10,000 samples in six endemic countries.

This week, the first results were published in the American Journal of Tropical Medicine and Hygiene’s Supplement dedicated to Falsified Medicines.

The news from our research is reassuring: of the 2,028 samples from Cambodia and Tanzania that we analysed, we did not find any fake medicines. But poor quality drugs still exist and are a great concern.

The importance of collecting samples in a representative way

This short video shows the importance of the methods that we used to collect antimalarial samples in the ACT Consortium drug quality programme, and how these differ from previous alarming reports:

The video is also available in French and in Portuguese.

In Tanzania, the study team used an “overt sampling” system, telling vendors that they were going to analyse the quality of their medicines. In Cambodia, researchers used overt sampling as well as a “mystery client” approach, where actors pretended to be patients with malaria, or their relatives, and bought the medicines offered to them.

Both studies used a randomised approach to sampling of drug outlets, which differs from previous studies that mostly used non-representative methods for selecting drugs for analysis. Here, study teams often select antimalarial sellers because they are easily accessible, or because they believe sellers are more likely to sell poor quality medicines based on their appearance or anecdotal reports. This “convenience approach” for sampling is not representative of the places where patients buy their medicines.

Substandard medicines: a great concern

Although our researchers did not find any falsified medicines in the samples collected from the two countries, they did find substandard drugs in Cambodia (31% of the samples collected) and in Tanzania (12% of the samples collected).

Substandard drugs can result from either inadequate quality control in the manufacturing process (meaning that they contain a lower or greater amount of the active pharmaceutical ingredient – or API – than intended), or well manufactured medicines may become degraded if they are kept in inappropriate storage conditions, for example in high heat or humidity.

Falsified medicines receive much attention globally, but substandard drugs worrying: not only do they leave patients with malaria undertreated, which could be fatal, but they may also contribute to the development of resistance to ACTs, the most effective drugs for malaria.

The results based on low cost convenience sampling approaches are still useful in drawing attention to the problem. However, alarming messages could be counter-productive by undermining the confidence in drugs and health care providers and systems.

It is important to ensure systems are developed and operate routinely to monitor drug quality. These studies are very costly, both for the collection and analysis of drugs. We need to develop approaches which are affordable and effective so that countries can sample medicines in a representative way and then target their efforts where they are needed.

Because just one fake drug is one too many!

Learn More

Results from Nigeria, Equatorial Guinea, Ghana and Rwanda will be published in the next few months. You can find updates at

The ACT Consortium studies in Tanzania and Cambodia are funded by a grant from the Bill & Melinda Gates Foundation to London School of Hygiene & Tropical Medicine. The Cambodia study also received support from the UK Department for International Development.