Diet, exercise, and weight loss can improve glycemic control, but most patients with type 2 diabetes eventually require glucose-lowering pharmacotherapy. An A1C goal of <7% (while minimizing hypoglycemia) is recommended for most patients to prevent or reduce the microvascular complications of diabetes (retinopathy, nephropathy, neuropathy). An A1C target of <8% may be appropriate for patients who are older, have comorbid conditions, or are at risk of serious hypoglycemia-associated adverse events.

Diet, exercise, and weight loss can improve glycemic control, but almost all patients with type 2 diabetes require antihyperglycemic drug therapy. Treating to a target A1C of <7% while minimizing hypoglycemia is recommended to prevent microvascular complications of diabetes (retinopathy, nephropathy, and neuropathy). An A1C target of <8% may be appropriate for some older patients.

Diet, exercise, and weight loss can improve glycemic control, but almost all patients with type 2 diabetes eventually require drug therapy. Treating to a glycated hemoglobin (A1C) concentration of <7% can prevent microvascular complications (retinopathy, nephropathy, and neuropathy), but whether it prevents macrovascular complications and death is unclear. An A1C target of <8% may be appropriate for older patients and those with underlying cardiovascular disease (CVD), a history of severe hypoglycemia, diabetes-related complications, a limited life expectancy, or a long duration of disease.

For many years, the goal of drug therapy for most patients with type 2 diabetes has been to achieve and maintain an A1C of <7%. Achieving that goal can prevent microvascular complications (diabetic retinopathy, nephropathy, neuropathy), but whether it prevents macrovascular complications (myocardial infarction [MI], stroke) has been less clear. The FDA now requires that cardiovascular safety studies be performed for all new drugs for type 2 diabetes.1 Recent findings that some of the newer second-line drugs for type 2 diabetes have cardiovascular benefits have led to new interest in the cardiovascular efficacy and safety of all antidiabetic drugs.

The goal of drug therapy for type 2 diabetes is to achieve and maintain a near-normal glycated hemoglobin (A1C) concentration without inducing hypoglycemia; the target is generally an A1C of ≤7%. Treating to this target has been shown to prevent microvascular complications (retinopathy, nephropathy, and neuropathy), but whether it prevents macrovascular outcomes is unclear. An A1C target of <8% may be appropriate for older patients and those with underlying cardiovascular disease, a history of severe hypoglycemia, diabetes-related complications or comorbidities, or a long duration of disease.

Canagliflozin (kan" a gli floe' zin; Invokana – Janssen), a sodium-glucose co-transporter 2 (SGLT2) inhibitor, has been approved by the FDA for oral treatment of type 2 diabetes.

Most experts agree that lifestyle modifications and metformin (Glucophage, and others) should be used first to treat patients with type 2 diabetes. If metformin alone fails to control hyperglycemia, there is no general agreement on which drug should be added next. A recent article in The Medical Letter offered some support for a sulfonylurea. Three recent trials published in The Lancet favored the long-acting basal insulin glargine, the glucagon-like peptide (GLP-1) analog exenatide, and the dipeptidyl peptidase-4 (DPP-4) inhibitor linagliptin, respectively. Some of the advantages and disadvantages of these and other available agents are listed in Table 1 on the opposite page.

The development of hyperglycemia in type 2 diabetes results from a combination of metabolic abnormalities that includes insulin resistance, diminished insulin secretion and excess hepatic glucose production. Diet, exercise and weight loss are helpful in improving glucose control, but most patients ultimately require drug therapy.

Metformin (Glucophage, and others) is generally preferred as the first-line agent for treatment of type 2 diabetes, but most patients subsequently require treatment with more than one drug. Many combination products have been marketed; the latest of these combines saxagliptin with extended-release (ER) metformin as Kombiglyze XR.

Liraglutide (Victoza – Novo Nordisk), a glucagon-like peptide-1 (GLP-1) receptor agonist given by subcutaneous injection, has been approved by the FDA for treatment of patients with type 2 diabetes. It can be used alone or in addition to oral antidiabetic drugs such as metformin (Glucophage, and others) or glimepiride (Amaryl, and others). Liraglutide is not recommended for first-line therapy and is not approved for use with insulin.

Saxagliptin (Onglyza - Bristol-Myers Squibb), the second oral dipeptidyl peptidase-4 (DPP-4) inhibitor to be marketed in the US, has been approved by the FDA for treatment of adults with type 2 diabetes.

A new fixed-dose tablet (PrandiMet - Novo Nordisk) combining metformin (Glucophage, and others) and repaglinide (Prandin) has been approved by the FDA for treatment of type 2 diabetes in patients already taking both metformin and repaglinide, or for patients not adequately controlled on either drug alone.

The development of hyperglycemia in type 2 diabetes results from a combination of metabolic abnormalities including insulin resistance, diminished insulin secretion and excess hepatic glucose production. Diet, exercise and weight loss are helpful in improving glucose control, but most patients ultimately require drug therapy.

The development of hyperglycemia in type 2 diabetes results from a combination of metabolic abnormalities including insulin resistance, excess hepatic glucose production and diminished insulin secretion. In many patients, diet and regular exercise can improve glucose control. Most drugs currently available for management of type 2 diabetes increase insulin supply (sulfonylureas, other secretagogues and insulin itself), decrease insulin resistance (thiazolidinediones) or improve the effectiveness of insulin (biguanides). Alpha-glucosidase inhibitors reduce the rate of glucose absorption. Newer agents such as pramlintide (Symlin) and exenatide (Byetta) have multiple effects to increase satiety and reduce postprandial hyperglycemia.

Two new fixed-dose combinations are now available for management of type 2 diabetes. Metaglip (Bristol-Myers Squibb), a combination of metformin and glipizide, is approved for initial therapy or as second-line treatment when control is not adequate on metformin or a sulfonylurea alone. Avandamet (GlaxoSmithKline), a combination of metformin and rosiglitazone, is approved by the FDA only as second-line therapy for patients who are not well controlled on metformin alone, or are already taking both metformin and rosiglitazone. Glucovance (Bristol-Myers Squibb), a combination of metformin and glyburide, a sulfonylurea similar to glipizide, has been available since 2000 (Medical Letter 2000; 42:105).

The development of hyperglycemia in type 2 diabetes results from a combination of metabolic abnormalities including insulin resistance, excess hepatic glucose production and diminished insulin secretion. Most drugs currently available for management of type 2 diabetes fall into 2 categories: those that increase insulin supply (sulfonylureas, other secretagogues and insulin itself) and those that decrease insulin resistance or improve its effectiveness (biguanides, thiazolidinediones). Alpha-glucosidase inhibitors reduce the rate of glucose absorption.

Nateglinide (Starlix), a new meglitinide oral glucose-lowering agent, has been approved by the FDA.

Rosiglitazone, the second thiazolidinedione derivative to be marketed in the USA for treatment of type 2 diabetes, has been approved by the FDA for use either alone or combined with meformin.

Repaglinide (Prandin - Novo Nordisk) is a new oral glucose-lowering agent for treating type 2 diabetes (formerly called non-insulin-dependent diabetes mellitus or NIDDM). It has been approved by the FDA for monotherapy or for use in combination with metformin.

Troglitazone (Rezulin - Parke-Davis), the first of a new class of thiazolidinedione derivatives ('glitazones') for diabetes, has been marketed for oral treatment of noninsulin- dependent diabetes mellitus (NIDDM) in patients who take more than 30 units of insulin daily and still have a glycosylated hemoglobin concentration (HbA1c) of 8.5% or higher.

Glimepiride (Amaryl - Hoechst Marion Roussel), a new sulfonylurea similar to glyburide and glipizide (Medical Letter, 26:79, 1984), was recently marketed for treatment of patients with non-insulin-dependent diabetes mellitus (NIDDM) not controlled by diet and exercise. The new drug is the first sulfonylurea approved by the US Food and Drug Administration (FDA) for use concurrently with insulin.

Acarbose (Precose -Bayer), an oral alpha-glucosidase inhibitor that has been available in Europe for several years, was recently approved by the US Food and Drug Administration (FDA) for treatment of non-insulin-dependent diabetes mellitus (NIDDM).

Metformin (Glucophage - Bristol-Myers Squibb), a hypoglycemic agent, was recently marketed in the USA for oral treatment of patients with non-insulin-dependent diabetes mellitus (NIDDM) not adequately controlled by diet alone. Previously marketed in more than ninety countries, including Canada, metformin (dimethylbiguanide) is chemically related to phenformin (phenylethylbiguanide), which was withdrawn from the US market in 1976 because it caused a high incidence of lactic acidosis. In approving metformin, the US Food and Drug Administration stipulated that a post-marketing controlled trial of 10,000 patients be conducted to determine the incidence of lactic acidosis.