Senegal is set to continue administering hydroxychloroquine to coronavirus patients, a senior health official said Thursday, after encouraging results for those treated with the venerable anti-malarial drug.

Both chloroquine and hydroxychloroquine are drugs ordinarily used to treat malaria, but early small-scale studies suggest they reduce virus levels among people badly infected by COVID-19.

Some countries have rushed to use the drugs but many scientists are urging caution until larger trials show whether they are safe and effective.

In a televised statement on Thursday, Moussa Seydi, the doctor in charge of treating Senegalese COVID-19 patients, said there was anecdotal evidence that people treated with hydroxychloroquine recovered faster.

"When it comes to science, observation alone is not enough and extensive research is needed before an opinion can be validated," he added, also urging people to avoid risky self-medication. "But the results we have seen reassure us and reassure my whole team, and we will continue in this direction."

Details about the trial in Senegal are scant. Seydi told AFP last week that about half of Senegal's COVID-19 patients were being treated with hydroxychloroquine. On Thursday, he did not offer any further details about dosage, the exact number under treatment, the age-range of the patients or whether they had any underlying medical conditions.

Senegal has recorded 195 confirmed coronavirus cases to date, of whom one has died. Chloroquine and hydroxychloroquine have been used for decades against malaria and are considered cheap and safe when used correctly. However, they also have potentially serious side effects, especially when taken in high doses or administered in tandem with other medications.

Seydi said that patients under his care had exhibited "no side effects," and that he and his team will trial combining hydroxychloroquine with the antibiotic azithromycin in the aim of achieving better results. 

The European Medicine Agency warned on Wednesday that neither chloroquine nor hydroxychloroquine should be used to treat COVID-19 cases, except for clinical trials or in the event of a "national emergency."