European health regulators have approved the use of Pfizer's pill 'Paxlovid' to treat COVID-19.
It's authorised for treating adults who do not require supplemental oxygen but are at risk of developing severe disease.
It's the first oral antiviral medicine to treat COVID-19 to be approved by the European Medicines Agency.
Regulators say the safety information about the new drug "was favourable and side effects were generally mild".
It does note that one of the substances in the drug - ritonavir - is known to affect the action of many other medicines, and the product information includes relevant warnings and advice about that issue.
However, the EMA has concluded that the medicine's "benefits are greater than its risks".
They pointed to a study involving over 1,000 patients showing that "treatment with Paxlovid significantly reduced hospitalisations or deaths in patients who have at least one underlying condition putting them at risk of severe COVID-19".
The EMA notes: "The majority of patients in the study were infected with the Delta variant.
"Based on laboratory studies, Paxlovid is also expected to be active against Omicron and other variants."
The European Commission is now set to fast-track approval for the use of the drug across the EU.
Earlier this month, Cabinet signed off on plans to spend €90m on antiviral and monoclonal antibody treatments made by Pfizer, Glaxo Smith Kline (GSK), and Merck (MSD).
Ireland is entering an EU joint procurement agreement to access the drugs.
The HSE is also trying to purchase them through bilateral agreements at national level.
Ministers said it was expected the pills could start arriving in Ireland within weeks.