La importancia de los fármacos antimaláricos

Why Antimalarial Medicines Matter

21.4.2015

[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]

 

As World Malaria Day 2015 approaches, we are able to reflect on some of the key drivers that will bring about malaria control and eventual elimination. Better prevention, improved diagnostics, new or updated treatments, joined-up health policies, sustained international funding and much more.

Yet there is one piece of the puzzle that is sometimes forgotten, or ignored, the issue of antimalarial medicine quality and drug treatment efficacy. By which we mean the quality of drugs and dosing of medicines administered to patients suffering from malaria.

There is an increasing body of evidence to suggest that significant quantities of medicines and medical products, especially in low and middle-income countries, are of poor quality. Malaria researcher and drug quality expert Professor Paul Newton at the University of Oxford and Head of Drug Quality at the Worldwide Antimalarial Resistance Network (WWARN) and Andrea Stewart, Head of Advocacy & Communications at WWARN explain the latest research evidence and explore some of the recommendations to improve medicine provision for patients.


Imágenes escaneadas de un blister falsificado frente a uno original.

Substandard medicines (due to errors in factory production) and falsified medicines (due to criminal fraud) are serious neglected global health problems. Poor quality medicines can cause avoidable morbidity, mortality, increased antimalarial drug resistance and loss of faith within health systems, especially in low and middle-income countries.

Administering falsified antimalarials, containing no antimalarial, does not itself cause antimalarial resistance, as the parasites are not exposed to any medicine in the blood. However, patients in areas of poor medicine quality when they remain ill may seek different medicines until their symptoms are relieved.  If they then take substandard antimalarials, caused by production errors and usually containing less than the stated amount of antimalarial, this may create a perfect environment for resistant parasites to persist in the blood stream, multiply and go on to reinfect other patients. 

This combination of both falsified and substandard medicines is likely to be a key driver for further resistance and, if left unchecked, could threaten the lives of millions.

The drug dose of the most widely used frontline antimalarials is also part of this complex treatment equation. We are fortunate to have highly effective Artemsinin Combination Treatments (ACTs) available to cure malaria in many endemic settings. However, their efficacy is under threat with the misuse of montherapies (a single drug, rather than a combination), and at times inadequate dosing of vulnerable groups such as small children. Recent analyses of the most widely used ACTs suggest that some dosing levels need to be revised in order to fine-tune the treatment of groups including pregnant women and babies.

Furthermore, global and national health policy decisions are often made using evidence generated from clinical trial reports. Until recently it was believed that trials were immune from the issue of medicine quality. However, recent research investigations suggest worrying evidence of poor quality medicines administered during patient trials.

One report of antimalarial drugs, planned to be used in a clinical trial for pregnant women in Africa, describes that once tested, one of the brands contained less than 90% of what the label stated.

Policy guidelines have improved the practice of medical research, especially clinical trials, and helped to ensure that trials are more carefully planned, implemented and reviewed.  However, recent studies into the quality of many medicines used in clinical trials, including antimalarials, suggest that trial guidelines need to urgently include details on how to monitor and safeguard the quality of medicines used.

If the quality of medicines within the supply chain and the dosing of antimalarials to treat patients suffering from malaria are more specifically defined and monitored, the impact on our efforts to control and contain malaria and drug resistance would diminish significantly. We could also reinforce the chain of evidence for health policy decision-making, spend less valuable funding on malaria treatment and restore patient confidence in the quality of medicines being used to treat malaria. These combined efforts would ensure that decades of life-saving malaria work will not be lost, and together that we can continue to work towards saving more lives, better malaria control, and eventual eradication of this deadly disease.

Learn More

Discover more on Antimalarial Drug Quality and the latest research evidence into antimalarial drug dosing at the Worldwide Antimalarial Resistance Network (WWARN), www.wwarn.org and @WWARN on Twitter.