Know Your Medicines
Is the antimalarial agent Chloroquine effective for the treatment of COVID-19? 抗疟药氯喹对COVID-19的治疗有效吗?

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The Take-Home Points:

Antimalarials like chloroquine and hydroxychloroquine are currently being studied for their effectiveness and safety when used to treat COVID-19. While Chloroquine may be purchased from a licenced pharmacist in Singapore for the prevention of malaria, we do not recommend self-medication for treatment of COVID-19 without proper medical assessment and evaluation. If you suspect that you could have COVID-19 infection or experiencing COVID-19 symptoms, seek medical attention immediately.


抗疟疾药(如氯喹和羟基氯喹chloroquine and hydroxychloroquine)目前正用於治疗COVID-19时有效性和安全性的研究。虽然可以从本国药剤师那里购买氯喹来预防疟疾,但我们並不建议您在没有适当医生检验的情况下自行用药治疗COVID-19。如果您怀疑自己可能感染了COVID-19或出现了相关症状,请立即就医。

The Issue

Media reports and social media have been buzzing with news of “effective treatment for COVID-19”. You might also have read claims that one of the medicines, Chloroquine, which is also used to treat malaria, “has [purportedly] been approved by the Food and Drug Administration (FDA) to treat COVID-19”. Since then, self-medication of chloroquine has led to several cases of poisoning in Nigeria. A second agent by the name of hydroxychloroquine has also been mentioned.



The Facts

In Singapore, chloroquine can be bought directly from licenced pharmacists for the prevention of malaria. Hydroxychloroquine is more often used for the treatment of medical conditions like Lupus and Rheumatoid Arthritis. It is only available with a doctor’s prescription.

Back in 2005, chloroquine was found to be active against the “SARS” virus in laboratory experiments. Hence, in the wake of the COVID-19 epidemic, the same group of scientists suggested that it may be useful against COVID-19 too. Since then, a French report described that COVID-19 infection was shortened by 6 days for more than half of the 24 participants with the use of hydroxychloroquine. Similarly, the Chinese describe the shortening of infection and prevention of worsening of pneumonia with chloroquine in 100 patients. However, just based on these reports, neither agencies like U.S. FDA nor Health Sciences Authority of Singapore can approve chloroquine for routine use in COVID-19 infections. A well-designed clinical trial is needed to prove effectiveness and safety of these agents before they can be licenced and labelled for COVID-19 treatment.

Besides, some risks are involved with the use of antimalarials and thus medical oversight is necessary. In people with Glucose-6-Phosphate Dehydrogenase (G6PD) deficiency, use of chloroquine and hydroxychloroquine can cause red blood cells to break down, leading to anemia and jaundice. Both agents may reduce blood sugar levels for people on anti-diabetic medicines. Occasionally, these medicines have been associated with adverse reactions related to the eyes and the heart. When used without the proper oversight of a trained healthcare professional or appropriate monitoring, one could suffer from serious side effects.

As mentioned in our first advisory published on 19 March 2020, there is currently no specific medicine recommended to prevent and/or treat COVID-19. Instead, we could look forward to the results for existing medicines that are repurposed like lopinavir-ritonavir combination pill (which could be used with interferon injection), chloroquine and ribavarin and new medicines like remdesivir, favipiravir and tocilizumab which are undergoing clinical trials.

For reliable and timely information on COVID-19, we point the reader to trusted agencies and their official websites. Some examples include the weekly Saw Swee Hock School of Public Health reports on COVID-19, the Centers for Disease Control and Prevention (CDC), U.S. FDA and the World Health Organisation (WHO) websites. For clarification or further information, do “Just Ask” your friendly pharmacist.






有关COVID-19的及时可靠信息,我们介绍读者以下可信赖的机構及其官方网站。例如,Saw Swee Hock公共卫生学院关于COVID-19的每周报告、疾病控制与预防中心(CDC),美国FDA和世界卫生组 (WHO)网站。有关澄清或更多信息,请询问您友好的药剂师。



  2. Coronavirus and chloroquine: Has its use been approved in US?
  5. Vincent MJ, Bergeron E, Benjannet S, Erickson BR, Rollin PE, Ksiazek TG, Seidah NG, Nichol ST. Chloroquine is a potent inhibitor of SARS coronavirus infection and spread. Virol J. 2005 Aug 22; 2:69.
  6. Colson P, Rolain JM, Raoult D. Chloroquine for the 2019 novel coronavirus SARS-CoV-2. Int J Antimicrob Agents. 2020 Mar;55(3):105923.
  7. Gao J, Tian Z, Yang X. Breakthrough: Chloroquine phosphate has shown apparent efficacy in treatment of COVID-19 associated pneumonia in clinical studies. Biosci Trends. 2020 Mar 16;14(1):72-73.
  8. Touret F, de Lamballerie X. Of chloroquine and COVID-19. Antiviral Res. 2020 Mar 5;177:104762.
  13. COVID-19 and medicines.


Authored by / 作者:

Ms Grace Kng, Dr Ng Tat Ming and Dr Doreen Tan Su-Yin

康莉琳, 黄达民 和 陈素音

Members of Pharmaceutical Society of Singapore / 新加坡药剂师协会

感谢 台湾年轻药师协会(Taiwan Young Pharmacists Group) 与林雪芬(Ms Stephenie Lim) 药剂师  协力翻译

21 March 2020