Antimalarials + Vitamin C ≠ Fire + Water

CLAIM: Twitter user claims that mixing malaria medication with vitamin C or fruit juice reduces the potency of the medicine.

INSUFFICIENT EVIDENCE: Research articles have explored findings from the interaction between vitamin C, its sources and ACTs. The effects though, have never been concluded on.

Full Text

In the past when antimalarials were prescribed, they would be prescribed with vitamin C supplements, and analgesics to aid the effects of the medication. However, according to a popular twitter account by the name of aproko doctor, we have it all wrong. He claims that Vitamin C negates the effects of antimalarials, rendering the medication inert; further retorting: “Don’t start a fire and quench it by yourself…”  

The tweet has garnered more than 5K retweets and over 6K likes, to date. In a thread, the doctor by the name Nonso (@aproko_doctor on twitter) later clarified that his tweet and the warning only applies to artemisinin-based combination therapy.

Malaria

Malaria is a life-threatening infectious disease of epidemic proportions. There are an estimated 100 million cases of malaria each year in Nigeria alone! As a matter of fact, it causes an estimated 300,000 deaths per year in the country. So it becomes headlines when the widely recommended treatment for malaria (e.g. chloroquine), utilized for over 5 decades is now ineffectual- in most tropical countries.

The succeeding recommended treatment method is not without its misgivings either. The artemisinin-based combination therapy used to control malaria is now suspected of being ineffective due to concurrent use with vitamin C (also referred to as ascorbic acid). This is concerning especially when the World Health Organisation (WHO) supposedly prioritizes the efficacy of antimalarials. 

Drug resistance and interaction are the two major issues that challenge efficacy. Drug resistance, especially antimicrobial resistance is a phenomenon in which microorganisms develop resistance to medications that hitherto were effective against the infection, while drug interaction refers to a reaction between two or more drugs or other substances that often renders the primary drug ineffective. This is particularly true when taken together. 

The tweet points to efficacy (explicitly, drug interaction) in suggesting that the potency of our malaria medications are reduced when taken with vitamin C or its sources.  

The standard treatment for malaria 

Artemisinin-based combination therapy (ACT) is currently the most effective medication available against malaria. It has been recommended by the WHO as the first-line treatment for uncomplicated malaria P.falciparum malaria (the most common and deadly form of the four malaria causing agents). 

ACT is a combination drug therapy method. It often involves a combination of 2 or more active ingredients that vary in their modes of action, to improve therapeutic efficacy. Artemisinin-based therapy comprises of artemether, artesunate or dihydroartemisinin; among artemisinin derivatives like amodiaquine, lumefantrine and mefloquine. However the underlying rationale behind this combination of antimalarials, according to the WHO was to counteract the ever-increasing rates of drug resistance (chloroquine remains the antimalarial with the highest rates of resistance). 

Do Antimalarials interact with Ascorbic acid? 

Dubawa reached out to the source of the claim, Aproko doctor, for verification. He referred us to a particular study as evidence of his claim. Interestingly, we found that this “study” is in fact, not an actual study, but a review of other studies. It primarily reviewed a specific study that was conducted seven years ago. In this study, the researchers sought to examine the effect of vitamin C on an artemisinin derivative- artemether; with mice as the test subjects. 

Red Flags

For one, this study was conducted on Plasmodium berghei infected mice! Laboratory studies frequently use this rodent model of malaria. Their argument centred around the assumption that the disease processes of a rodent in studies such as this, equated and subsequently applied to research in human subjects. However, researchers have called into question its application to humans as this form of malaria does not affect people. 

Additionally, to reach a solid conclusion, there would be a need to repeat this study in human subjects. The doses of vitamin C used in mice would have to have an equivalent quantity utilized in human subjects; in order to ascertain the levels that would be classed as “high” in humans.

More so, Drugs.com, a reputable pharmaceutical encyclopedia makes no mention of ascorbic as a source of possible interaction. It is also worth noting that major health organisations like the WHO has not put out such a warning. However, Drug.com does identify numerous other medications that range from castor oil to codeine and tramadol as possible interactives. To find out if your medication might be on this list, read more here. 

Conclusion 

Research articles have explored findings from the interaction between vitamin C, its sources and ACTs. The effects though, have never been concluded on. Hence, there really is not enough evidence to make this assertion. Similar to the drug trial process, studies have to undergo several tests (humans inclusive) before a solid conclusion can be made. Otherwise, they are just hypothesis and medical suggestions.