A review of published and
unpublished studies looking at the quality of antimalarial drugs in
southeast Asia and sub-Saharan Africa has found that more than a
third failed quality testing.
The study found that 36 per cent of samples taken in Asia were falsified, while this was the case for around 20 per cent of the African samples. There were also more cases of failed packaging in Asia than Africa, at 46 per cent and 36 per cent, respectively.
Most worryingly, the authors of the review suggest the data may be an underestimate of the scale of the problem.
"The issue may be much greater than it seems because most cases are probably unreported, reported to the wrong agencies, or kept confidential by pharmaceutical companies," they write in The Lancet Infectious Diseases journal.
Compromised quality among antimalarials is likely to have contributed to the emergence of treatment-resistant Plasmodium falciparum identified on the Thailand–Cambodia border, which has been a source of resistant strains of the malaria parasite in the past.
The researchers call for a multifaceted approach to address the problem of poor quality antimalarials, including the speedy implementation of the intergovernmental mechanism put forward by the World Health Organization earlier this year which is designed to separate the public health issues posed by substandard and counterfeit medicines from intellectual property considerations (see WHO adopts new resolution on counterfeit medicines).
They also say that national medicine regulatory bodies need urgent support, particularly for the 30 per cent of agencies around the world "that have either no drug regulation or a capacity that barely functions".
Other elements of their proposed plan include improved and internationally agreed methods for detecting poor-quality drugs to improve the reliability of data on the penetration of these materials in the marketplace, access to simple field-testing devices for medicine inspectors and awareness-raising programmes.
Greater access to free or inexpensive antimalarials - particularly artemisinin-based combination therapy (ACT) which is the most effective treatment for the disease at the moment - would reduce the financial incentives for counterfeiters and encourage better manufacturing standards.
"These findings are a wake-up call," conclude the authors. "Concurrent interventions and a multifaceted approach are needed to define and eliminate criminal production, distribution, and poor manufacturing of antimalarial drugs."