Pfizer,best known as the maker of Viagra, is considering stockpiling medicines as Britain hurtles towards Brexit without a deal

Pfizer, the world's biggest drugs company, best known as the maker of Viagra, is considering stockpiling medicines as Britain hurtles towards Brexit without a deal.

The US firm, which made £40 billion of sales last year, said it had 'undertaken work to ensure we can continue to supply in the EU and the UK covering all Brexit scenarios'.

Pharmaceutical firms fear a no-deal Brexit will disrupt supplies to and from the European Union.

Johnson & Johnson, another of the world's biggest drugs companies, said it is also preparing for the worst, explaining: 'We are exploring all options to ensure that patients continue to have access to the medicines they need.'

It follows revelations last week that France's Sanofi and Switzerland's Novartis are increasing stocks in case supplies from the EU are disrupted.

The new Health Secretary, Matt Hancock, said last week that the NHS is also preparing to stockpile medicines in case Britain leaves the EU without a deal.

UK drugs giant AstraZeneca has said it is increasing its stocks by about a fifth.

Pfizer said: 'We have carried out detailed assessments of the supply of all our medicines with the focus on ensuring we will continue to have them available for our patients.'

The key ingredient for Viagra is made in Ireland, but the pills are manufactured in France.

Pfizer and Johnson & Johnson are both urging the UK and EU to strike a 'mutual recognition agreement' for the regulation and supply of medicines.