Chloroquine is Dead, Long Live Chloroquine

The death knell for chloroquine (CQ), a cheap and relatively long lasting antimalarial drug, have been tolling across the continents in a westerly direction for decades and finally reached West Africa in the 1990s. In southern Africa, Malawi was one of the first countries to officially discontinue use of CQ in 1993. A recent article in the New England Journal of Medicine (NJEM – subscription required) reports that when CQ was no longer available in either the public or private health systems of Malawi, the mutated P. falciparum gene associated with drug resistance disappeared.

The drug is now effective again at treating malaria in parts of Malawi– but before too much excitement develops for the drug that is 1/20th the price of currently recommended artemisinin-based combination therapies (ACTs), the authors of the NJEM article caution that CQ is still available throughout the rest of the continent and will not regain its former strength until it disappears entirely as was the case in Malawi. Only then could CQ be reintroduced, but in combination with other antimalarial drugs to prevent resistance from returning. But what are the chances that CQ will be taken off the shelves any time soon, and what does this say about malaria drug policy in endemic countries?

Nigeria, for example, adopted a new ACT-based drug policy in 2005, which was greeted with the headline “Government bans Chloroquine as first line drug in malaria treatment” in a prominent national daily, which required a response by the Federal Ministry of Health a few days later, “Chloroquine Not Banned, Says Minister”. In this milieu it has been a major challenge to convince state and local government health services to adopt the new national malaria drug policy and use their limited essential drug funds to buy ACTs. Supplies from donors, whether the Global Fund or the World Bank, are not adequate, nor are they intended to cover the ACT needs of the total population.

Not surprisingly, CQ and sulphadoxine-pyramethamine (SP), another cheap antimalarial drug to which parasites are resistant, are available and being used for treatment in local government clinics in the southeastern part of the country, an area where CQ resistance is highest. ACTs are rare or non-existent in these rural settings, even in drug shops whose owners are reluctant to buy these expensive alternatives not knowing whether their customers can pay. It is only in the urban private medicine shops and pharmacies that one sees a plethora of ACTs, and unfortunately also monotherapy artesunate drugs.

So, the pressure remains to buy and sell or dispense CQ. One key factor is education of both public and private providers, many of whom have not heard about the new drug policy. Education will not be enough until, as an accompanying NJEM editorial says, the cost of ACTs is comparable to what people have been paying for CQ and SP.

As a final concern, researchers are finding that CQ may be valuable in the treatment of HIV. HIV and malaria produce some very negative synergies so it is not clear what the practical implications of continued use of CQ for HIV might be, but it does raise the possibility that CQ may not disappear soon, and we may not be able to replicate the Malawi experience after all.

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