Pfizer's pill becomes first US-authorized home COVID treatment

Washington: As Omicron variant spreads globally, the United States on Wednesday authorized Pfizer Inc's (PFE.N) antiviral COVID-19 pill for people aged 12 and older at risk of severe illness, making it the first oral and at-home treatment for Covid.

The announcement comes at a time when the data from Pfizer's clinical trial showed its two-drug antiviral regimen was 90% effective in preventing hospitalizations and deaths in patients at high risk of severe illness. Recent lab data suggests the drug retains its effectiveness against Omicron.

Pfizer's Paxlovid (nirmatrelvir tablets and ritonavir tablets, co-packaged for oral use) has been approved for the treatment of mild-to-moderate coronavirus disease (Covid-19) in adults and paediatric patients (12 years of age and older weighing at least 40 kg) with positive results of direct SARS-CoV-2 testing.

The pill has also been approved for those at high risk for progression to severe Covid-19, including hospitalisation or death.

In a statement issued on Wednesday, the FDA said that Paxlovid is available by prescription only and should be initiated as soon as possible after diagnosis of Covid-19 and within five days of symptom onset.

Patrizia Cavazzoni, director of the FDA's Center for Drug Evaluation and Research noted that the authorisation introduces the first treatment for Covid-19 that is in the form of a pill that is taken orally -- a major step forward in the fight against this global pandemic.

"This authorisation provides a new tool to combat Covid-19 at a crucial time in the pandemic as new variants emerge and promises to make antiviral treatment more accessible to patients who are at high risk for progression to severe Covid-19," Cavazzoni added.

However, Paxlovid is not authorised for the pre-exposure or post-exposure prevention of Covid or for initiation of treatment in those requiring hospitalisation due to severe or critical Covid-19.

The pill is also not a substitute for vaccination in individuals for whom Covid-19 vaccination and a booster dose are recommended. The pill is not authorised for use for longer than five consecutive days.

"Possible side-effects of Paxlovid include impaired sense of taste, diarrhoea, high blood pressure and muscle aches. Using Paxlovid at the same time as certain other drugs may result in potentially significant drug interactions," the FDA said.

Using Paxlovid in people with uncontrolled or undiagnosed HIV-1 infection may lead to HIV-1 drug resistance.

"Ritonavir may cause liver damage, so caution should be exercised when giving Paxlovid to patients with pre-existing liver diseases, liver enzyme abnormalities or liver inflammation," the FDA warned.