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.

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.

The goal of drug therapy for type 2 diabetes is to achieve and maintain a near-normal A1C concentration without inducing hypoglycemia; the target is generally an A1C of <7.0%. Treating to this target has been shown to prevent the microvascular complications of retinopathy and nephropathy, but whether it prevents macrovascular outcomes remains unclear. Three large trials found that intensive glucose control did not reduce the incidence of macrovascular events. One of these trials (ACCORD) in >10,000 patients with type 2 diabetes, with or at high-risk for cardiovascular disease, found that treating patients intensively with antihyperglycemic drugs to an A1C target of 6.0% for a mean of 3.7 years did not significantly reduce the incidence of major cardiovascular events (the primary endpoint) and was associated with increased all-cause mortality compared to patients treated to an A1C target of 7.0-7.9%. An A1C target of 7-8% may be prudent in older patients and in those with underlying cardiovascular disease, severe hypoglycemia, or multiple diabetes-related complications or co-morbidities.

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 FDA has approved Juvisync (Merck), a fixed-dose combination of the antihyperglycemic DPP-4 inhibitor sitagliptin (Januvia) and the HMG-CoA reductase inhibitor simvastatin (Zocor, and others).

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.

Linagliptin (Tradjenta – Boehringer Ingelheim/Lilly), a third oral dipeptidyl peptidase-4 (DPP-4) enzyme inhibitor, was recently approved by the FDA for treatment of type 2 diabetes, either alone or in combination with metformin, a sulfonylurea or pioglitazone

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.

The cardiovascular safety of the thiazolidinedione rosiglitazone (Avandia – GlaxoSmithKline) is in the news again, with some authorities calling for its removal from the market (New York Times, February 19, 2010).

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.

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.

Pregabalin (Lyrica - Pfizer) is the first drug approved by the FDA for management of fibromyalgia. When it was first marketed, pregabalin, which is structurally similar to gabapentin (Neurontin, and others), was approved for treatment of neuropathic pain associated with postherpetic neuralgia and diabetic peripheral neuropathy and for adjunctive treatment of partial onset seizures in adults with epilepsy. It has also been prescribed off-label for other types of neuropathic pain such as sciatica.

The thiazolidinediones rosiglitazone (Avandia) and pioglitazone (Actos) are peripheral insulin sensitizing agents used to treat hyperglycemia in patients with type 2 diabetes; one or the other is often used as a second or third agent with metformin (Glucophage, and others) and/or a sulfonylurea such as glimepiride (Amaryl, and others). A recent report suggested that rosiglitazone may increase the incidence of myocardial infarction (MI) and cardiovascular mortality.

For patients with diabetes poorly controlled with a single oral drug, addition of a second drug with a different mechanism can be helpful. A fixed-dose combination (Actoplus met - Takeda) of two widely used antihyperglycemic drugs, the thiazolidinedione pioglitazone (Actos) and the biguanide metformin (Glucophage, and others), has been approved by the FDA for management of type 2 diabetes. It is indicated for patients already being treated with both pioglitazone and metformin or as second-line therapy for those not adequately controlled with either metformin or pioglitazone alone. Rosiglitazone, another thiazolidinedione, is also available in a fixed-dose combination with metformin (Avandamet).

Pregabalin (Lyrica - Pfizer), a structural analog of gamma-aminobutyric acid (GABA) similar to gabapentin (Neurontin - Pfizer, and others), which recently became available generically, has been approved by the FDA for treatment of neuropathic pain associated with postherpetic neuralgia (PHN) and diabetic peripheral neuropathy (DPN), and for adjunctive treatment of partial onset seizures in adults with epilepsy.

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.

Polycystic ovary syndrome (PCOS), an endocrine abnormality characterized by hyperandrogenism and anovulation, affects 5-10% of women of reproductive age in the US. It is often accompanied by obesity and insulin resistance. In recent years, antidiabetic drugs, although not approved for such use by the FDA, have been tried for treatment of this disorder. This review describes the effectiveness of metformin and the thiazolidinediones in women with PCOS. Also included is a dosage and cost table for some insulin-sensitizing drugs.

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.

Full-page advertisements in newspapers are urging patients with type 2 diabetes coming off Rezulin to ask their doctors to switch to Avandia or Actos. Troglitazone was withdrawn from the market on March 21 because of rare but severe hepatic toxicity.

Pioglitazone is the third thiazolidinedione ("glitazone") to be marketed in the USA for treatment of type 2 diabetes. Thiazolidinediones decrease resistance to insulin.

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.