She further stated that remdesivir, made by Gilead Sciences Inc, has also been shown to kill the virus at late stages.
The NAFDAC boss however noted the cost for treating people with chloroquine was way cheaper than remdesivir.
While remdesivir cost $2,500 to treat an average patient, chloroquine only cost $10.
She also noted West African nations like Ghana, Togo and Senegal have embraced the clinical use of chloroquine for treatment.
Adeyeye disclosed these during a virtual press conference on Tuesday in Abuja.
She said: “In the cells, in the lab, remdesivir and chloroquine killed covid-19. At what stage would they be more effective? We didn’t know at that point. Now we are realising that chloroquine is effective at the early stage.
“I was watching CNN about 4 or 5 days ago, and there is this surgeon – Sanjay Gupta. For the first time he mentioned that chloroquine can be used prophylactically.
“I said – maybe chloroquine can work. I made the press briefing, and stated that it is only for clinical trial treatment because until you do a very robust clinical trial, you cannot say that it is going to work.
“Remember, remdesivir and chloroquine work in the cells. Chloroquine was proven to work in 100 patients. We did not know at that time that the disease has about four phases – pre-exposure stage, early stage, mild stage, and the severe stage.”
Adeyeye added: “When we now got the profile of remdesivir, what was recorded in literature and from the manufacturer was that remdesivir doesn’t work at the early stage. It works at the late stage.
“But when viruses are in the tube in the laboratory, you won’t know which is late or which is early. Both killed them. We are now understanding that it is not only one drug that can be effective for covid-19 but it depends on the stage and the phases of the disease.”