The first time TenOever and his collaborators gave the drug to hamsters in his lab, in early June, it offers a lot of protection against the virus that Covid-19 causes. ‘We thought,’ Oh, OK, that was weird. Let’s do it again, ” tenOever says. They were constantly repeated and saw good results. Then the research team, which includes Donald Ingber of the Wyss Institute in Boston, showed that, in human lung cells, the drug reduces the levels of a harmless virus that is designed to carry the same spike protein as the pandemic. “It works beautifully,” says tenOever.
Others are not so convinced by the results. “The surrogate virus is not the same,” says Vincent Racaniello, a microbiologist at Columbia University in New York, referring to human lung cell tests. Racaniello points to design limitations of the study as this and says that evidence at present is not sufficient to warrant testing of amodiaquin in humans.
Notably, when other researchers tested hamster and human lung cells with hydroxychloroquine or chloroquine, they came down low. Just to be concerned, TenOever and its collaborators also performed a direct, head-to-head comparison of amodiaquine and hydroxychloroquine in hamsters, with a common control group. Amodiaquine reduced the amount of viral material. Hydroxycholorquine net. (The experiment did not measure differences in live virus.)
Sunil Parikh, a malaria researcher at the Yale School of Public Health who is part of a separate group conducting lab tests of amodiaquine against Covid-19, notes that the hamsters in the new study all received the medicine one day for exposure to the pandemic virus. As a result, there is no way of knowing what might happen if the medicine is given to an animal that is already sick. “The results of the hamster model are impressive for demonstrating potential prophylactic activity, but do not help to show one potential for treatment,” says Parikh.
The results of the new study intrigue Isaac Bogoch, a clinical researcher at the Toronto General Hospital Research Institute who specializes in infectious diseases. “I find it completely interesting,” he says. “But if the result of this is that people save amodiaquin and thereby self-medicate and doctors claim that they have found a cure, that is obviously the wrong answer, and we have been there and done that already.”
The hydroxychloroquine debacle underscores the deep dangers of drug hype in the absence of clinical trial data – not only for people taking a useless drug with potential side effects, but for anyone else reasons that drugs are needed. When the U.S. government bought stores of hydroxychloroquine for use in the pandemic, and the number of prescriptions for it went through the roof, when rumors spread about the potential use in the pandemic, patients who trusted her for years were to treat ailments lupus began to run short. (This past spring, one in three lupus patients said they had difficulty getting their pills.) With amodiaquine, the same withdrawal behavior could be even more disastrous. It is used in the second-most common combination treatment for malaria, a disease that claims the lives of nearly half a million people each year, the majority of whom are children in Africa under the age of five.
“If we have a situation with amodiaquine like we had with hydroxychloroquine stocking, it will have an enormous effect on countries to have the required treatments for malaria, and potentially have a major impact on increasing malaria mortality,” says Peter Olumese, a medical officer in the World Health Organization’s Global Malaria Program. Amodiaquine is also given to healthy children to prevent malaria infection during the rainy season in countries such as Nigeria and Chad. In these situations, the medicine is usually given three days a month. Last year, 20 million children received the drug.
There is one more complication in the fact that amodiaquine is currently not available in the US. Research in the 1980s documented liver damage in chronic users for malaria prevention; and there were also signs that when lifted at high doses, the medication may cause abnormalities in heart rhythm. Parikh says that compliments any potential use of amodiaquine as a preventative drug against Covid-19. “Prophylactic trials are quite challenging, and when amodiaquine was used as a prophylactic in travelers in the West, it was pulled for toxicity,” he says.
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