The Medicines and Healthcare products Regulatory Agency (MHRA) has issued a warning to diabetes patients, urging them to check their insulin pens and cartridges following a precautionary recall of specific batches of the NovoMix 30 Flexpen 100U/ml pre-filed pen and the NovoMix 30 Penfill 100 U/ml cartridge.

A manufacturing issue concerning a fault in the filling of cartridges has resulted in some batches of the pens and pen cartridges containing the wrong amount of insulin.

In 2012, over one million of these insulin pens and cartridges were dispensed in England. The manufacturing problem is believed to affect around only 0.14 per cent of all cartridges sold across Europe, and the MHRA believes the safety risk to diabetes patients in the UK is ‘likely to be limited to a small number of people’.

Patients are urged to check their batch numbers and consult their GP or nurse to arrange a new supply.

Judith Gledhill, head of personal injury at Thompsons Solicitors, said: “Diabetics know only too well the consequences of too much or too little insulin.

“While the MHRA has announced that the number of people affected by the manufacturing fault is likely to be minimal, it’s crucial that patients are made aware of the issue so that any potential risks can be negated.

“Unfortunately, faulty products do reach the public, and at Thompsons we’ve worked on a number of cases supporting people who have been affected by dangerous or defective products.”

The following batch numbers, printed on the pen or cartridge, are believed to be affected: CS6D422, CS6C628, CS6C411, CP50912, CP50750, CP50639, CP51706, CP50940, CP50928, CP50903, CP50914, CP50640, CP51095, CP50904, CP50650, CP51098, CP50915, CP50412, CFG0003, CFG0002, CFG0001, CP50902, CP50749, CP50393, CP50950, CP51025, CP50751, CP50375, CP50420, CP51097, CP50641, CP51096 and CP50392.