Second-line therapy for patients with diabetes

Medication

In combination with lifestyle measures (weight control, proper nutrition, and adequate exercise), medications, such as metformin, play an important role in managing glycemic control in patients with diabetes mellitus:

  • Metformin is a popular first-line oral antidiabetes drug that is used to help control glycemic levels in patients with diabetes when lifestyle modifications alone are not sufficient.

If metformin monotherapy fails, most patients need one or more oral antidiabetes drug, or insulin, added to their treatment regimen to achieve target glycemic levels. In Canada, seven classes of antidiabetes drugs are available that may be used as second-line therapy: sulfonylureas, meglitinides, a-glucosidase inhibitors, thiazolidinediones, incretin agents, weight loss agents, and insulins (human and insulin analogues).

Condition

Diabetes mellitus is a chronic disease characterized by the body’s inability to produce enough insulin or to use it properly. The condition is classified as follows:

  • Type 1 diabetes results when little or no insulin is made by the body. 
  • Type 2 diabetes results when the body makes insulin but is unable to use it effectively. 
  • Gestational diabetes presents during pregnancy as glucose intolerance and is usually a temporary condition.

An estimated 2.4 million Canadians have diabetes: 90% of patients have type 2 diabetes mellitus and 10% have type 1 diabetes mellitus. For patients with diabetes, health care costs and costs attributable to premature death and lost productivity exceed more than $9 billion per year. Canada’s aging population and rising rates of obesity suggest that the number of Canadians with type 2 diabetes mellitus will continue to increase.

The chronic complications of diabetes mellitus affect many organs and are responsible for the majority of mortality and morbidity associated with the disease.

Health care providers, consumers, and policy makers require timely, evidence-based information they can rely on to help treat this disease.

Scope of second-line therapy topic

Optimal second-line therapy for patients with diabetes inadequately controlled on metformin is one of a number of topics that COMPUS has taken on in conjunction with our overall diabetes management priority area.

Topics include:

When metformin monotherapy is no longer effective, existing guidelines recommend several options for second-line therapy. However, these guidelines generally lack specific recommendations regarding which drug(s) are optimal as second-line therapy. Instead, they typically recommend that a stepwise approach be used to add drugs from various classes. Moreover, guideline recommendations in this area are based primarily on evidence regarding clinical efficacy and safety; cost-effectiveness is often not considered.

Given the large, growing population of patients with diabetes in Canada, suboptimal use of second-line antidiabetes drugs is likely to have a detrimental effect on both health outcomes and the cost-effective use of drugs. There is a need for clear recommendations based on clinical- and cost-effectiveness evidence to guide the choice of second-line therapy in patients with diabetes inadequately controlled on metformin.

Refer to our Project Status web page to find out what stage we are at in this project.