Metformin Rarely Prescribed to Prevent Diabetes

Although metformin can help prevent diabetes onset in those at high risk, the medication is rarely prescribed for this purpose.

A new study published in the Annals of Internal Medicine evaluated the use of metformin in 17,352 patients aged 19 to 58 years with prediabetes, a health state indicated by abnormally high blood sugar levels. The analysis revealed only 3.7% of these patients were prescribed metformin between 2010 and 2012.

In an exclusive interview with Pharmacy Times, lead study author Tannaz Moin, MD, MBA, MSHS, described several possible culprits behind low metformin use among prediabetics, including poor provider and patient awareness of evidence surrounding diabetes prevention, a reluctance to "medicalize" prediabetes, and the drug’s lack of FDA approval for use in diabetes prevention.

“It is likely that many factors contribute simultaneously and this is going to be an important area of needed future study,” Dr. Moin told Pharmacy Times.

Given their medication knowledge and relationships with both prescribers and patients, pharmacists can play an important role in increasing the use of metformin in patients with prediabetes, Dr. Moin noted.

“Pharmacists have expertise in metformin prescription data, including existing safety considerations,” she said. “This expertise can help both providers and patients make more informed decisions surrounding metformin use.”

Dr. Moin recommended that pharmacists educate patients about evidence-based treatment options for diabetes prevention and provide them with an overview of the relative risks and benefits of preventative metformin therapy to help them make appropriate treatment decisions.

“Patients with prediabetes have varying levels of risk, and there are trade-offs with every treatment choice, so it is critical that we engage patients in a fully informed and shared decision-making process,” Dr. Moin told Pharmacy Times.

Her research team also found:

• 4.8% of prediabetic women were prescribed metformin, compared with 2.8% of prediabetic men.
• 6.6% of obese patients with prediabetes were prescribed metformin, compared with 3.5% of prediabetics who were not obese.
• 4.2% of prediabetics with at least 2 other chronic diseases received prescriptions for metformin, compared with 2.8% of prediabetics with no other chronic diseases.

The authors acknowledged a number of potential study limitations, including a lack of access to data on participation in lifestyle programs, possible misclassification of prediabetes and metformin use, and their inability to independently verify patients' eligibility to receive metformin.