Access to quality antimalarials – determining the scale of the problem
The proliferation of poor quality medicines has been described as a global pandemic that threatens the lives of millions. Poor quality medicines can have a devastating affect on the lives of patients, resulting in prolonged sickness, treatment failure, side effects, loss of income, and death.
It is understood that antimalarial medicine quality is an important contributing factor in Plasmodium falciparum resistance to antimalarial drug treatment using artemisinin combination therapies, or ACTs. However, thus far it has been difficult to accurately estimate the scale of the problem, and to assess changes over time. One contributing factor is that evidence is often based on surveys that use ‘convenience’ sampling rather than ‘random sampling’ to collect the medicines investigated for authenticity. As such, the results often under or over-estimate the actual prevalence of poor-quality medicines.
WWARN’s Medicine Quality Group is sharing expertise and collating information to increase our understanding of the prevalence and distribution of poor-quality medicines around the world. To develop our understanding of the severity of the issue, research teams at the London School of Hygiene & Tropical Medicine and others confirmed that an estimated one third of the antimalarial medicines collected in a survey in Cambodia between 2010 and 2011 were outside the expected range of the stated active pharmaceutical ingredient.
“The first step in the fight against poor quality medicines is their identification. Medicine regulatory authorities (MRAs) in many low- and middle-income countries have limited financial and human resources to tackle the problem,” says Prof Paul Newton, Head of the WWARN Medicine Quality Group.
In 2003, a random survey of antimalarial medicines in Laos found that 84 per cent of artesunate tablets tested - a then commonly used antimalarial - did not contain the correct pharmaceutical ingredients. In 2012, WWARN’s Medicine Quality Group led a repeat of this survey and all of the antimalarials contained the correct pharmaceutical ingredients. This was very good news in Laos’ battle against falsified antimalarials. However, although none of antimalarials were falsified, the team found that over one quarter of samples were either substandard or had begun to degrade over time. The results demonstrate that Laos has gone some way to respond to the threat of falsified medicines over the past decade, but there is much more work to be done globally to reduce the availability of substandard medicines.
Recent studies from ACTWatch, who work to improve access to quality assured antimalarials, highlight a growing problem in the Democratic Republic of Congo (DRC), Nigeria and Kenya in the availability of non-quality assured artemisinin combination therapies (ACTs). Non-quality assured antimalarials can lead to decreased drug efficacy and slower rates of malaria parasite clearance – key indicators of drug resistance.
In Kenya, the studies found that one out of five antimalarials distributed nationwide in 2014 were ACTs that were not from a quality-assured source. In Kinshasa, DRC, in 2013, an estimated 40 per cent of antimalarials distributed were confirmed as non-quality assured ACTs. Additionally, availability and distribution of non-artemisinin therapies including sulphadoxine pyrimethamine (SP) and quinine was common, even though these antimalarials are not recommended by the World Health Organization as first-line treatments against falciparum malaria infection due to elevated risks of drug resistance.
Non-artemisinin therapies, as well as artesunate tablets, were also found to be widely available in a study in 2013 in Nigeria. These findings pose a major threat to effective control of malaria disease (non-artemisinin therapies) and to sustained artemisinin drug efficacy (artesunate tablets).
“The growing availability and use of non-quality assured ACTs across Africa is of great concern given the potential threat of substandard ACTs to artemisinin drug efficacy’ says Dr. Megan Littrell, Principal Investigator for ACTWatch.
Addressing the critical gap in our knowledge of the overall quality of antimalarial treatments, the WWARN Antimalarial Quality (AQ) Surveyor supports the efforts of national and international organisations working to provide malaria patients with quality-assured, effective medicines. This mapping tool delivers customised summaries of published reports of antimalarial medicine quality across regions and over time.
It is clear that to make serious progress towards the challenge of poor quality medicines we will need even more coordination and resources to build upon our baseline understanding of the true scale and impact of substandard and falsified medicines.
To find out more about our Medicine Quality Group email Céline Caillet: medicinequality@wwarn.org