What Is Chloroquine, And Why Do People Think It Treats Coronavirus?

Do not buy these medicines from online pharmacies without a prescription from your health care professional. Consumers should not take any form of chloroquine that has not been prescribed for them by a healthcare professional. Serious poisoning and death have been reported after mistaken use of a chloroquine product not intended to be taken by humans. If you have these medicines in your home, keep them in childproof containers out of the reach of children to prevent accidental poisoning. For prevention and treatment of malaria in infants and children, the amount of chloroquine phosphate is based on the child’s weight. Your doctor will calculate this amount and tell you how much chloroquine phosphate your child should receive.

Per-protocol analysis was not performed because of the impossibility of monitoring drug administration twice a day at the hospital. Radiologic findings were presented in this article only at the baseline due to the inability to perform careful analyses of available computed tomography scans over time. There is no specific antiviral therapy recommended for coronavirus disease 2019 (COVID-19). In vitro studies indicate that the antiviral effect of chloroquine diphosphate requires a high concentration of the drug.

Doctors should not prescribe chloroquine prophylaxis unless patients are traveling to areas where the malaria parasite is susceptible to treatment. Irreversible damage to the eyes has been reported by some people who have taken high doses or chloroquine or used it for long-term treatment. An eye exam should be done before starting treatment, during treatment, and after treatment. If you take antacids, they need to be separated from chloroquine administration by at least 4 hours. Chloroquine phosphate is the one available in the United States as a generic. The dosing is based on the amount of chloroquine in the pill, or the “base” amount.

Administration of this drug and these agents should be separated by at least 4 hours. For acute malaria attacks in adults the initial dose is 1 g followed by an additional 500 mg after 6 to 8 hours, then 500 mg 24 and 48 hours after the first dose. The patient’s renal function should be checked at baseline, then after 1 month, after 3 months, and then every 4–6 months to assess for any changes in risk for adverse ocular effects (more frequent surveillance is needed if laboratory values are abnormal or with high-risk patients) . The patient’s full blood count should be checked prior to treatment and monthly for the first 3 months, then every 4–6 months .

Moreover, they found that chloroquine was significantly effective even when the drug was added 3 to 5 h after infection, suggesting an antiviral effect even after the establishment of infection. Since these researchers obtained similar results by NH4Cl treatment of Vero cells, the underlying mechanisms of action of chloroquine and NH4Cl might be similar and might be attributed to the alkaline properties of both compounds . Interestingly, our time-of-addition experiments with HCoV-OC43 pointed out that chloroquine was required at the moment of infection to block HCoV-OC43 replication. When added at the time of infection, chloroquine reduced the viral load by 2 logs in comparison to the positive control value. At later time points, a loss of antiviral activity of chloroquine was noted.

In this way, an effective antiviral chloroquine concentration can be reached. Antiviral measurements were based on the reduction in viral titer of coronavirus-infected cells. HRT-18 cells were seeded at a density of 6 × 104 cells per well into a 24-well culture plate. After 4 days of growth, cells were infected with 1 × 106 HCoV-OC43 copies per ml in the presence of various concentrations of chloroquine ranging from 0.032 to 500 μM. After 4 days of incubation at 37°C in the presence of 5% CO2, cell supernatants were collected. Viral RNA was extracted using the QIAamp viral RNA kit to determine the viral RNA load in the cell supernatant by using the qRT-PCR described above.

The measurement of the viral load shows that chloroquine is required at the moment of infection to block the HCoV-OC43 replication (Fig. 1). When chloroquine was added at the time of infection, viral RNA could still be detected, but the viral load was reduced 100-fold in comparison to the positive control viral load. At later time points, a loss of the antiviral activity of chloroquine was noted. Though nearly a dozen drugs to treat coronavirus are in clinical trials in China, just one—remdesivir, an antiviral that was in trials against Ebola and the coronavirus MERS—is in full-on trials in the US. So a promising drug would be great—and even better, chloroquine isn’t new. Its use dates back to World War II, and it’s derived from the bark of the chinchona tree, like quinine, a centuries-old antimalarial.

Here — with hat tips to Stanford chemical engineer and subcellular-compartment spelunker Monther Abu-Remaileh, PhD, and virologist Jan Carette, PhD — I describe one key way chloroquine grapples with SARS-CoV-2 within the nano-scale boxing ring that is a cell. In Part 1 and Part 2 of a series called “What’s a virus, anyway?” I described the general features of viruses and the specifics of how coronaviruses launch their invasion of our cells. SOLIDARITY is testing four treatments—remdesivir , the HIV drugs lopinavir/ritonavir (Kaletra; AbbVie) alone or with interferon beta 1a, which is normally used to treat multiple sclerosis, and hydroxychloroquine—in patients hospitalized with COVID-19. Lambasted for maintaining its flights to China at the height of the pandemic, Ethiopian Airlines has stood its ground and currently operates flights to and from Europe, the new epicentre of the coronavirus outbreak. This makes the carrier one of the last companies still operating intercontinental flights.

In conclusion, we demonstrate here that chloroquine shows strong in vitro and in vivo antiviral activities against HCoV-OC43. Moreover, treatment with daily doses of chloroquine has a long-lasting protective effect against lethal coronavirus OC43 infection in newborn mice. The Mayo Clinic lists 14 drugs that shouldn’t be taken with chloroquine, whose side effects can include blurred vision, nausea, vomiting, cramps, headache, and diarrhea. Similar side effects are associated with hydroxychloroquine, another form of the drug, which is also linked to convulsions and “mental changes” by the US National Library of Medicine. The start of a clinical trial to test the drug chloroquine as a treatment for the coronavirus pandemic, announced over the weekend by President Donald Trump, provoked a clamor for the unproven drug, amid reports of shortages.