Pharmacists should expect ‘long term supply issues’ of metformin 500mg/5ml oral solution after manufacturers found it contained unacceptably high levels of a cancer-causing agent, the Department of Health and Social Care (DHSC) announced. 

The widely used drug — which is used to treat and prevent type 2 diabetes — has been temporarily discontinued by its primary manufacturer and recalled by another after both found traces of N-nitrosodiethylamine (NDMA) impurities.  

The drugs are currently undergoing testing and will be out of stock until testing is complete, DHSC said yesterday (13 September). 

Limited supplies of metformin 500mg/5ml oral solution are expected to be made available at the beginning of October, however, these supplies of the drug will not be enough to support full demand. 

Various formulations of the drug, including  850mg/5ml and 1000mg/5ml oral solutions and   500mg powder for oral solution remain available but cannot support any potential increase in demand. 

Although supplies of metformin 500mg/5ml oral solution specials can be sourced, there is concern that these may also contain NDMA and therefore specials are only prescribed when ‘all other options have been exhausted’, PSNC said in its own update.  

The following specialist importers have currently confirmed they can source unlicensed metformin 500mg/5ml oral solution:

Earlier this month, The Pharmacist reported that prescribing for diabetes in primary care now accounts for 12.5% of the total spend on all prescription items in England. 

The cost of anti-diabetic drugs to the NHS, such as metformin, sulfonylureas and SGLT2 inhibitors has risen by 62% in the past five years to a high of £686 million, the NHS report showed.