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.

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.

The FDA has removed prescribing and dispensing restrictions placed on rosiglitazone (Avandia, and others) in 2010 because of concerns about its cardiovascular safety.1 The removal of restrictions was based on the results of an independent reevaluation of the RECORD trial, which found no significant difference between rosiglitazone and metformin/sulfonylurea in the risk of cardiovascular (or unknown cause) death, myocardial infarction, or stroke.2

1. FDA Drug Safety Communication: FDA requires removal of some prescribing and dispensing restrictions for rosiglitazone-containing diabetes medicines. Available at www.fda.gov. Accessed January 27, 2014.

2. KW Mahaffey et al. Results of a reevaluation of cardiovascular outcomes in the RECORD trial. Am Heart J 2013; 166:240.

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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.

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.

The goal for drug therapy of type 2 diabetes is achieving and maintaining a near-normal glycated hemoglobin (HbA_1C) concentration without inducing hypoglycemia; the target has generally been an HbA_1C of 6.5-7.0% or lower. Whether treating to this level prevents macrovascular (cardiovascular) events has been unclear. Now, 2 large randomized, double-blind trials in patients with long-standing diabetes and at high risk for cardiovascular disease have found no decrease in macrovascular events with intensive glucose control.

The ACCORD trial in about 10,000 patients found that patients intensively treated with anti-hyperglycemic drugs, including frequent use of thiazolidinediones, mostly rosiglitazone (Avandia), and insulin, with an HbA_1C target of 6.0% (actual median HbA_1C 6.4%) did not obtain a significant reduction in major cardiovascular events (the primary endpoint) over a period of 3.5 years. The trial was stopped early because of an unexpected increase in all-cause mortality (257 deaths vs. 203) in intensively treated patients compared to patients with an HbA_1C target of 7.0-7.9% (actual median HbA_1C 7.5%). The etiology of the higher mortality is unclear.1

The ADVANCE trial in about 11,000 similar patients treated to an HbA_1C target of 6.5% with a sulfonylurea-based regimen, and infrequent use of thiazolidinediones, also found no decrease in macrovascular events, but no increase in all-cause mortality.2

Whether intensive glycemic control would reduce macrovascular events in patients at lower risk has not been established.

1. The ACCORD Study Group. Effects of intensive glucose lowering in type 2 diabetes. N Engl J Med 2008; 358:2545.
2. The ADVANCE Collaborative Group. Intensive blood glucose control and vascular outcomes in patients with type 2 diabetes. N Engl J Med 2008; 358:2560.

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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.

Avandaryl, a new fixed-dose tablet combining the thiazolidinedione rosiglitazone (Avandia) and the sulfonylurea glimepiride (Amaryl, and others), was recently approved by the FDA for treatment of type 2 diabetes. It is approved for patients already taking a combination of rosiglitazone and a sulfonylurea or those not adequately controlled on rosiglitazone or sulfonylurea monotherapy. Rosiglitazone is also available in a fixed-dose combination with metformin (Avandamet). Most patients with type 2 diabetes eventually require 2 drugs with different mechanisms to control hyperglycemia.

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.

Infertility occurs in about 15% of couples. About one third of infertility is due to problems with ovulation or an anatomic abnormality of the fallopian tube or peritoneum, such as scarring, adhesions or endometriosis. Another third is due to a male infertility factor, most commonly insufficient sperm production or abnormal motility or morphology. The remaining third is unexplained. In older women unexplained infertility is probably caused by diminished quality and quantity of oocytes, decreased implantation and spontaneous pregnancy wastage.

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.