Chloroquine, an old antimalarial is being repurposed for the clinical trial treatment of Coronavirus 2019-nCoV. The drug was first tested in vitro (in the lab) using standard assays to measure the effects on the cytotoxicity, virus yield and infection rates of 2019-nCoV. The drug was reported to function as antiviral at both the entry and post-entry stages of 2019-nCoV infection. Chloroquine has also recently been reported as potential broad spectrum antiviral drug.
In a very recent publication, chloroquine was reported in a press briefing by the State Council of China, indicating that chloroquine phosphate had demonstrated marked efficacy and acceptable safety in treating COVID-19 associated pneumonia in a multi-center clinical trials conducted in China. The study involved 10 hospitals in Wuhan, Jingzhou, Guangzhou, Beijing, Shanghai, Chongqing and Ningbo, and 100 patients. The investigators reported that chloroquine phosphate is superior to the control in inhibiting the pneumonia associated with COVID-19, and shortening the course of the disease.
Chloroquine was discontinued in Nigeria many years ago for use as antimalarial because of the resistance that the parasite developed against the drug. Therefore, sourcing the raw material – active pharmaceutical ingredient (API) – chloroquine phosphate could be difficult.
Aboutfour weeks ago, I approached a local manufacturing company (May and Baker), a member of Pharmaceutical Manufacturing Group of Manufacturing Association of Nigeria (PMGMAN), whose flagship product in the past was chloroquine to make a batch of the drug for emergency stock. The company had NAFDAC approval for the production of the drug as antimalarial many years ago before the discontinuation.
The Managing Director expressed possible difficulty in getting the API due to the fact that the drug has been discontinued. He called shortly after that he was able to get the API and was asked to manufacture a batch foremergency stock just in case more people become exposed and infected with the virus. The batch has been manufactured and the company plans to make more batches if needed.
As stated in my press briefing on March 20, 2020, NAFDAC is giving expedited provisional approvals for the manufacture of any commoditiesfor preventing contracting the disease (sanitizers) and drug or medical device that could be used for the clinical trial testing and treatment of COVID-19 pandemic. The Agency had reduced the 120 working days for approval to 10 days due to the crisis. The productsshould havebeen previously reported for clinical trial treatments in reputable scientific journals or technical literature as safe and effective.
Other researchers in France, US have used the drug for clinical trial treatment of COVID-19 and they reported effectiveness of the drug. Lagos State will be starting a clinical trial on chloroquine to evaluate the effectiveness.
Chloroquine works by increasing endosomal pH from the acidic environment required for virus/cell fusion,resulting in the inhibition of infection of SARS-CoV. It also interferes with the glycosylation ofcellular receptor, angiotensin-converting enzyme 2. This may inhibit the virus-receptor binding and terminate the infection.The antiviral and anti-inflammatory effects of chloroquine contribute to the efficacy in treating COVID-19 patients.
NAFDAC advices the public to desist from its use without the guidance of a medical doctor or clinician for cases of clinical trial treatment of COVID-19. It has side effects such as gastrointestinal upset, blurred vision, headache and pruritis (itching). The itching can be relieved by using antihistamine. Prolonged use can also cause retinopathy or vision impairment.
The Agency, through her regulatory activities will ensure that the clinical trial protocol guidelines are followed and wishes the clinical researchteams great success in stopping the raging pandemic. The mandate of NAFDAC is to safeguard the health of the country.
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Prof Mojisola Christianah Adeyeye, PhD, FAS