Paxlovid: what is the pill against Covid approved by Anvisa

Anvisa (National Health Surveillance Agency) approved, this Wednesday (30), the emergency authorization of Paxlovid, a drug to treat Covid-19 from pharmaceutical Pfizer.

The indication of the drug is for people who have tested positive and are at risk of progressing to severe cases – which must be evaluated by doctors -, are over 18 years old and do not need to make artificial use of oxygen through machines.

Its main action is to prevent the worsening of the health conditions of infected people.

In addition to Brazil, the drug already has approval for emergency use in the United States, European Union countries, Canada, China, Australia, Japan, the United Kingdom and Mexico.

How does Paxlovid work?

Pfizer’s drug, known as a protease inhibitor, is designed to block an enzyme the virus needs to multiply. When taken along with a low dose of another antiviral pill called ritonavir, it stays in the body longer.

Three pills should be taken twice a day for five days.

The sale is made only under medical prescription and the use should not be done without medical supervision.

Among the contraindications are cases that require hospitalization for severe manifestations of Covid-19, as well as prophylaxis (does not work to protect yourself from the virus before contact).

The drugmaker’s CEO, Albert Bourla, said the pill has “the potential to save patients’ lives, reduce the severity of Covid-19 infections and eliminate up to nine out of 10 hospitalizations”.

Clinical trial results

Covid-19 vaccines are seen as the best way to control the pandemic, but there is also a demand for treatments that can be done at home, especially for infected vulnerable people.

Interim data from the treatment clinical trial of 1,219 high-risk patients newly infected with Covid-19 showed that 0.8% of those taking Paxlovid were hospitalized, compared with 7% of patients receiving placebo.

They were treated within three days of the onset of disease symptoms.

There were seven deaths among those who received the placebo — and none in the group that took the pill.

When treatment began within five days of the onset of symptoms, 1% of the group taking Paxlovid ended up hospitalized, but no deaths were recorded. In the placebo group, 6.7% of patients were hospitalized and 10 deaths were recorded.

The patients who participated in the study, which has not yet been published or reviewed, were elderly or had an underlying health problem that put them at greater risk of developing the severe form of Covid-19.

All of them had mild to moderate symptoms of the disease.

“The success of these antivirals potentially marks a new era in our ability to prevent the serious consequences of SARS-CoV2 infection. [vírus causador da Covid-19]and is also a vital element in the treatment of clinically vulnerable people who may be unable to receive or respond to vaccines,” said Stephen Griffin, associate professor at the University of Leeds School of Medicine, UK.

Pfizer is also studying the impact of treatment on people at low risk of contracting the disease and on those who have already been exposed to the virus by someone in their household.