A tongue-tied Boris Johnson slipped up live on air during a briefing from Downing Street as he tried to say the name of the difficult to pronounce drug "tocilizumab".
The Prime Minister provided the nation with an update on the UK's coronavirus vaccination rollout on Thursday after millions of elderly and vulnerable Brits received a jab.
He also spoke of findings, published earlier in the day but which have not yet been peer-reviewed, which have showed that the immunosuppressive drugs - Actemra, also known as tocilizumab, and Kevzara, also known as sarilumab - reduced death rates by 8.5% among patients hospitalised and severely ill with coronavirus.
That would mean that for every 12 patients treated with one of the two drugs, an extra life would be saved, said Anthony Gordon, an Imperial College London professor of anaesthesia and critical care who co-led the study.
Despite the slip-up, the PM took the mistake in his stride and in good humour as he quipped the drugs will "soon be on everybody's lips".
Announcing that they will now be made available on the NHS during a Downing Street briefing, Prime Minister Boris Johnson said: "I want to thank everyone involved in this extraordinary national effort.
"All the GPs, nurses, pharmacists, and all the staff behind the scenes.
"Our armed forces, local councils, our scientists, who have not only developed the Oxford AstraZenica vaccine and the first-ever life-saving treatment of Covid in the form of dexamethasone, but also I am pleased to tell you today that British scientific research has now contributed to the creation of more, new life-saving treatments that have just passed rigorous clinical trials.
"In particular, tos... tocilizumub, sorry I'll say it again. Tocilizumab and sarilumab. And they'll shortly be on everybody's lips.
"Which have been found to reduce the risk of death for critically ill patients by almost a quarter and they reduce time spent in intesive care by as much as 10 days.
"These life-saving drugs will be available through the NHS with immediate effect."
The PM also said that almost 1.5 million people had now been vaccinated and that the Government intended to give everyone in care homes a jab by the end of January.
Speaking at a Downing Street press conference, the Prime Minister said: "We've now vaccinated 1.26 million people in England, 113,000 in Scotland, 49,000 in Wales and 46,000 in Northern Ireland.
"So, all together, nearly 1.5 million people across the UK have now received their first dose and within two to three weeks all of them will have a very considerable degree of immunity.
"It is thanks to the arrival of the Oxford/AstraZeneca vaccine, which can be stored at room temperature, that we can accelerate the pace of vaccination in care homes.
"We're using that vaccine in care homes for the first time today and by the end of the month we hope to have offered every elderly care home resident a vaccine."