The scenario of a so called "Hard Brexit" (U.K. to leave the EU with no deal*) is still a possibility. Thus, people need to think about this and make the necessary preparations.
As a response to the recent EU exit no-deal legislative proposals, the U.K. Medicines and Healthcare Products Regulatory Agency (MHRA) has issued an updated guidance defining some proposed arrangements if the U.K. will leave the EU on 29 March 2019 with no deal.
For medicines, some of the key arrangements include:
automatically converting Centrally Authorised Products (CAPs) to UK Marketing Authorisations (MAs), a process known as 'grandfathering'
targeted assessment of new applications for products containing new active substances or biosimilars which have been submitted to the EMA and received a Committee for Medicinal Products for Human Use (CHMP) positive opinion
a full accelerated assessment for new active substances
a period until the end of 2021 to amend packaging and leaflets for a product already on the market
allowing the parallel import of medicinal products that hold a marketing authorisation from an EU or EEA country
*UK would leave not only the EU but also the EU's Single Market (of which non-EU countries are also members) and the EU Customs Union (of which non-EU countries are also members).