Counterfeit anti-malarials containing the Viagra API were probably manufactured in Southeast Asia, researchers found.
Analysis of ten anti-malarials found many substandard, poor quality and counterfeit products in Ghana, Nigeria and other African countries. Evidence suggests the products were imported from Asia.
“Pollen analyses of the counterfeit anti-malarials were consistent with an origin in eastern Asia, but do not prove this. No evidence was found, from pollen analysis, of counterfeit pharmaceutical production in Africa”, the researchers wrote in Malaria Journal .
Counterfeit products linked to eastern Asia contained unexpected active pharmaceutical ingredients (APIs). Other anti-malarials, paracetamol and sildenafil, the API in Viagra, were all found in products.
The 10.4mg of sildenafil researchers found in each DHA-piperaquine tablet could “cause unexpected penile erection” and, particularly if the patient suffers from hypotension, “unknown complications”.
Rise of resistance
Over the longer term resistance from using substandard, poor quality or counterfeit artemisinin-based combination therapies (ACT) could me more damaging to the fight against malaria in Africa.
“Unless action is taken quickly, poor ACT quality and profligate use of monotherapy, whether genuine or poor quality, will contribute to the failure of ACT”, the researchers from Interpol, the US Centers for Disease Control and Prevention, and many other organisations wrote.
Researchers have yet to prove the link between low quality drugs and artemisinin resistance but models suggest low doses are a factor. Substandard drugs that result in blood concentrations too low to kill hardy strains could select for drug resistance and create a major long-term problem.
The researchers wrote: “Poor ACT quality, along with poor prescribing and poor adherence, would provide a fertile environment for the spread of artemisinin-resistant parasites. This would destroy the renewed hope for malaria control in Africa and kill many patients who would otherwise survive.”
Investment in development and distribution of anti-malarials is wasted if patients take poor quality medicines. Money should also be spent on regulators, the researchers wrote, and to add to the three African countries with World Health Organization (WHO) prequalified quality control laboratories.
Efforts are also needed to raise standards at the source. “Much more attention needs to be paid to substandard medicines, with inspection and facilitation of good quality production”, the researchers wrote.