Nitazoxanide antiparasitic, also known by the trade name Annita, against Covid-19 had a similar result to placebo
According to a study funded by the Ministry of Science and Technology, the use of the antiparasitic nitazoxanide (also known by the trade name Annita) against Covid-19 had a similar result to that of placebo. Even so, the research was the reason for the ceremony with the presence of President Jair Bolsonaro and Minister Marcos Pontes (Science and Technology) – at the event, a generic graphic said that the drug was effective and could help fight the pandemic.
“In summary, we now have a tool that the Ministry of Health can use to help save lives,” said Pontes, at the event on the 19th. “You can get a sense of what we are announcing here today, right? We are announcing something that will start to change the history of the pandemic. “
The results of the study, made available in pre-print (that is, not yet published and reviewed by other researchers), are significantly more modest than those cited by Pontes.
According to doctors and researchers heard by the report, the conclusion of the research does not change the current scenario and should not mean a turn in the fight against the new coronavirus.
The research authors themselves were more careful than the minister in presenting the observed result. “In patients with moderate Covid-19, there was no difference in symptom resolution after five days between the groups that used nitazoxanide and those that took placebo,” they wrote.
But, also according to the research, the drug is safe for patients with Covid-19 and leads to a reduction in viral load, which was considered a secondary result, according to the research design.
This decrease was one of the only details highlighted at the ceremony in which Pontes and Bolsonaro participated. The problem is that reducing your viral load doesn’t mean much on its own. As the study itself concluded, this did not translate into an abbreviation of the symptoms of the disease.
The research, funded by the Ministry of Science and Technology via CNPq (National Council for Scientific and Technological Development), was carried out with 475 adult patients with Covid-19 and aimed to verify whether nitazoxanide helped in the reduction of cough, fever and fatigue. It doesn’t help, says the research.
Despite being randomized, multicentric and double-blind (that is, it divides patients into random groups, who do not know whether they are taking the drug or placebo, all of which characteristics increase their methodological quality), the study has a number of limitations, recognized by the authors themselves.
To begin with, a broader analysis of the drug’s effects was not made, but only of three symptoms of Covid-19. Patients were followed up for only five days.
In addition, only participants who continued to have symptoms (49 of those taking nitazoxanide and 46 of the control group) were followed up for longer. Finally, it is not possible to know if the medication was properly taken, following the guidelines given by the authors of the research.
“The main result is that there was no difference between the two groups in the primary outcome”, says Natália Pasternak, PhD in microbiology from USP and president of the Instituto Questão de Ciência, which points out other methodological problems in the research, such as exclusions of study participants afterwards randomization, which could skew the results. The research authors excluded patients who, for example, had adverse effects and were hospitalized.
The researcher criticizes the way in which only patients with symptoms were followed up after five days. According to her, this can skew the result.
“The only positive outcome they had was viral load, which has no clinical and epidemiological relevance”, says the researcher.
The announcement made by Bolsonaro and Pontes, in addition to inflating the search results, had at least one other error. “I talked to him [Pontes] also and he told me that of those people who used this medicine [nitazoxanida], no person has even been hospitalized, “said Bolsonaro.
The statement is not true. According to the study data, five patients who were taking nitazoxanide were hospitalized for the clinical worsening and two were admitted to the ICU.