The island's supplies of OxyNorm, a powerful painkiller used by patients with conditions ranging from cancer to severe migraines, have run short.

As an opioid, the pharmaceutical is a controlled drug and therefore requires special clearance to be imported.

“My husband has spoken with several pharmacists because as each pharmacy ran out, they would send you to another one,” the wife of a man with chronic back pain.

“They were quite frustrated and concerned, so it's not just the patients.”

She said a friend with cancer depended on the easy-to-swallow gel caps and struggled with alternative pills.

Long-term patients are also subject to withdrawal symptoms if their regimen is interrupted.

According to John Turner, the pharmacy manager for Bermuda General Agency Limited, the shortage emanated from a delay with the preparation of clearance documents in the UK.

“Unfortunately, it's out of our control, but we are working with the vendor to have the product expedited to us,” he said.

While the island had a supply of the controlled release product, Mr Turner said everything was being done to resume supplies.

“There are many facets in the supply that are outside of our direct control, and it can be easy for a problem to occur.”