US guidelines updated to recommend metformin as first-line type 2 diabetes treatment

US physicians have published new guidelines recommending metformin as the primary drug to treat people with type 2 diabetes who require medication.
The American College of Physicians (ACP) says metformin is an effective treatment strategy for improving high blood sugar, and the American Academy of Family Physicians has endorsed the guideline. The ACP’s previous update on type 2 diabetes treatments came in 2012.
“Metformin, unless contraindicated, is an effective treatment strategy because it has better effectiveness, is associated with fewer adverse effects, and is cheaper than most other oral medications,” said Dr Nitin S. Damle, ACP president.
The ACP also recommends other medications; sulphonylureas, thiazolidinediones, SGLT-2 inhibitors and DPP-4 inhibitors, as additional treatments when a second medication is needed.
In the UK, metformin has been the first-line treatment for people with type 2 diabetes for many years. The ACP’s new guidelines are now closer to how the NHS prescribes medications.
This new guideline was based on a systematic review of randomised controlled trials and observational studies of oral drugs used to treat type 2 diabetes.
The primary outcomes of the studies included HbA1c, blood pressure, heart rate, all-cause mortality and diabetes-related complications such as retinopathy, neuropathy and nephropathy.
GLP-1 receptor agonist drugs were not evaluated in the guideline, but they were included in the full effectiveness review.
The guideline states that, before a second drug is prescribed, patients and clinicians should discuss the benefits and adverse effects that might be experienced.
The review appears online in the Annals of Internal Medicine.