Diabetes patients have been advised to stop using and return specific lots of Accu-Chek Aviva and Accu-Chek Performa test strips due to concerns they may give falsely high or low readings.
The Medicines and Healthcare products Regulatory Agency (MHRA) said it is estimated that more than 260,000 packs have been affected.
It warned the test strips, commonly used by diabetics for blood glucose testing, may give increased strip error messages prior to dosing with blood and in some cases may give falsely high or low readings, which may be hard to detect.
Dan Howarth, head of care at Diabetes UK, said inaccurate readings could mean patients over or under-dose with insulin, which can cause problems with hyper and hypoglycaemia.
If anyone finds that they have test strips from the affected lots, they are advised to seek alternative testing methods and return affected lots to their pharmacy or shop where they will be offered a replacement.
It is important people check their test strips and if necessary seek alternatives as soon as possibleJohn Wilkinson, MHRA
Anyone with concerns about their blood glucose readings should also speak to their doctor or another healthcare professional.
MHRA said the over-the-counter products affected are Accu-Chek Aviva in packs of 50 strips with lot numbers 497392, 497391, 496915, 496809, 496802 and 496807, and 10 strips with lot numbers 497344 and 497392.
Accu-Chek Performa in packs of 10 strips with lot numbers 476597 and 476646 are also included in the recall.
Accu-Chek Inform II test strips have also been recalled but are supplied in the UK by Roche for professional use only.
John Wilkinson, MHRA director of medical devices, said: “It is important people check their test strips and if necessary seek alternatives as soon as possible.
“If people have any questions about their blood glucose readings when using these test strips and meters they should speak with their doctor or pharmacist.
“We continue to encourage people to report any issues involving medical devices to the MHRA via our Yellow Card Scheme.”
Mr Howarth added: “It is incredibly important that people living with diabetes are able to rely on the technology that is designed to help them manage their blood sugar, so we’d strongly recommend that anyone using these test strips check their batch numbers and get replacement strips accordingly.
“Inaccurate readings could mean you over or under-dose with insulin, which in the short term can cause problems with hyper and hypoglycaemia.
“If you’re worried about your readings, we’d recommend speaking to your GP or a pharmacist as soon as possible.”