Drug shortages in the UK have risen to their worst level for four years, official figures show, with Brexit considered a key reason so many medications are scarce.

Drug companies notified the Department of Health and Social Care (DHSC) about disruptions to supply 1,938 times during last year – the highest number since the 1,967 seen in 2021.

Medications to treat epilepsy and cystic fibrosis are among those that pharmacists are finding it hard or impossible to get hold of, creating risks for patients’ health.

The figures have emerged in a new report by the Nuffield Trust health thinktank, which obtained them under freedom of information laws from the DHSC, which oversees the availability of drugs UK-wide.

The number of supply disruptions fell after 2021, to 1,608 in 2022 and 1,634 in 2023. But it suddenly shot up again last year to 1,938, the data shows.

Mark Dayan, a policy analyst at the Nuffield Trust and its Brexit programme lead, said: “This wave of medicine shortages has already meant people struggle to find the drugs their doctors told them were needed for conditions like epilepsy and cystic fibrosis. It’s very worrying that it appears to be rolling on at full force into a third year.”

The report says that while drug shortages have become a problem globally in recent years, the UK is facing “a worsening situation” compared with the rest of Europe because of Brexit.

“Elevated and troubling levels of medicine shortages are continuing, with no consistent sign of improvement. The UK has had the lowest import growth in medicines of any G7 country, driven by a reduction in EU imports,” the thinktank adds.

United Nations trade data, which Dayan and his colleagues analysed, shows that the UK “once again has the lowest rise in imports of medicines of all G7 countries since 2010”.

“The total value [of imports] has fallen by almost 20% since 2015, the year before the EU referendum, in cash terms – an indication of how medicine supply chains have shifted away from the UK,” the report says, with “little sign of a stable recovery since”.

HM Revenue and Customs data shows there has been “a decline [in imports] focused clearly on imports from the EU, adding to the evidence that new trade barriers related to Brexit are a likely explanation”.

In addition, UK drug exports to the European Economic Area – the 27 EU states plus Norway, Iceland and Lichtenstein – have fallen by a third since before the UK voted in 2016 to leave the EU.

The National Pharmacy Association voiced alarm earlier this month about “a growing crisis in medicine supply”. All 500 of the pharmacies it surveyed said they could not dispense a prescription at least once a day because drugs were unavailable.

“Pharmacies are at the sharp end of medicines shortages and frequently have to turn away distressed, frustrated and sometimes angry patients,” said Nick Kaye, the NPA’s chair.

He urged ministers to allow pharmacists to offer patients a safe alternative to their usual medication if it is not available, to help them manage their condition. “It is particularly frustrating for pharmacists to be unable to meet a clear need when they have a perfectly safe and effective solution in their pharmacy already,” he added.

Dayan warned that with the EU taking concerted action to reduce drug shortages by sharing supplies and increasing its domestic production, “there is a real risk we will be left out as the EU unveils big plans to safeguard its own supply”.

Brexit “does seem to have pushed us out of some European supply chains”, he added.

A DHSC spokesperson said: “This government inherited ongoing global supply problems, but we have robust measures in place to mitigate disruption for patients. We are strengthening our domestic resilience further by investing up to £520m to manufacture more medicines, diagnostics, and medical technologies in the UK.

“We are also working closely with the NHS, regulators and other key partners to cut red tape to grow our life sciences sector, and with international partners to bolster supply chains.”