9.3% of malaria drugs currently sold in Nigeria are of poor quality.

This is according to a study published in  PLOS ONE which analysed more than 3,000 anti-malaria drugs purchased in Enugu.

Researchers found 1.2% of the samples to be falsified and 1.3% to be degraded, but raised bigger concerns about 6.8% being of substandard manufacture, leaving patients at risk of not receiving the correct treatment dose and potentially contributing to the development of resistance to the main drug used to treat malaria.

The drug quality team of the Artemisinin-based Combination Therapy (ACT) Consortium at the London School of Hygiene and Tropical Medicine analysed 3,024 anti-malaria drugs containing artemisinin (the component that makes malaria treatment effective) from Enugu.

The area has an approximate population of about 3.3 miilion.

Dr Harparkash Kaur, who led the team said while the results raise concerns, they are reassuring in comparison with previous reports that found that more than 35% of antimalarials in sub-Saharan Africa failed chemical content analysis – in other words, were poor quality.

According to Guardian, the team purchased medicines from 421 outlets in Enugu including pharmacies, patent medicine vendors, and public health facilities.

In addition to ‘convenience’ sampling, which lacks systematic guidance on which outlets to sample from, samples were also bought from a representative sample of outlets.

For the study, the team used a covert approach, using “mystery clients” in which researchers pretended to be patients with malaria, or their relatives, asking to buy medicines; and an “overt” approach, where researchers told vendors openly that they were going to analyse the quality of their malaria medicines.

Then each sample was analysed in three independent laboratories in the UK and USA and classified as acceptable quality, falsified (fake drugs which do not contain the stated active pharmaceutical ingredient or API), substandard (which contain inadequate amounts of the active ingredients), or degraded (decomposition of the API by poor storage conditions, such as heat and humidity).

All three sampling methods detected falsified drugs, but the prevalence was higher in samples purchased using the convenience approach.

Artemisinin-based monotherapy tablets, which are no longer recommended by the World Health Organization because they do not include the partner compound that makes it an effective artemisinin-based combination therapy were also identified by the team.