Study: Counterfeit Antimalarials Discovered in Southeast Asia

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What: A 2004 study published in the Journal of Tropical Medicine and International Health found that an “alarmingly high proportion of antimalarial drugs bought in pharmacies and shops in Southeast Asia are counterfeit,” impeding treatment of malaria across the region.

Who: Pharmacies selling antimalarial drugs across Southeast Asia (SE Asia); counterfeit copies of drugs produced by Guilin Pharma and Mepha, Ltd.

When: February 2002–February 2003

Where: Southeast Asia, including Myanmar (Burma), Lao PDR (Laos), Vietnam, Cambodia and Thailand (map)

How: Multinational cross-sectional survey, studying artemisinin derivatives and mefloquine, used in combination to treat falciparum malaria.

Additional details:

Between February 2002 and February 2003, the studys’ authors sent buyers to purchase samples of antimalarial drugs from drug sellers, shops and pharmacies in western Thailand, Vietnam, Cambodia, Lao PDR and Myanmar.

A total of 303 samples were obtained from the five countries. Of the 188 artesunate blister packs that were collected, 53 percent (99 in total) were counterfeit, containing trace or no artesunate. Compared with a similar study done between August 1999 and August 2000, there was a 15 percent increase in the proportion of fake tablets.

In contrast, mefloquine tablets did contain some of the active drug; however nine percent of the collected tablets (44 in total) were substandard, containing an average of 18.1 mg instead of the standard 250 mg. The studys’ authors noted that the visual characteristics of the counterfeit medication were “indistinguishable from the genuine product.”

All of the fake artesunate tablets from the study were labeled as produced by Guilin Pharma, based in Guanxi, China. The proportion of Guilin Pharma tablets, both genuine and counterfeit, was highest in Cambodia at 94 percent.

The studys’ authors noted that artesunate tablets labeled as produced by Guilin Pharma have become increasingly targeted by counterfeiters, and that fake Guilin Pharma packaging—particularly the hologram sticker on the blister packs—has become more sophisticated “to the extent that they have become almost indistinguishable from the genuine product.”

All of the fake mefloquine tablets were labeled as made by Mepha Ltd., based in Aesh-Basel, Switzerland.

Counterfeit malaria medications have plagued malaria-prone regions for more than a decade. In 1999 alone, 30 patients in Cambodia died as a result of treatment from counterfeit antimalarials.

Related sources:

Fake antimalarials in Southeast Asia are a major impediment to malaria control: multinational cross-sectional survey on the prevalence of fake antimalarials,” The Journal for Tropical Medicine and International Health. December 9, 2004.

Official alert for fake artesunate in Southeast Asia, Center for Disease Control. July 2006. With full references concerning counterfeit antimalarials in SE Asia.

Counterfeit and Substandard Antimalarial Drugs, Center for Disease Control. July 2006.

Fact sheet on counterfeit medicines, World Health Organization. November 2006.

Fact sheet on the prevention and treatment of falciparum malaria. World Health Organization. February 2009.