Insulin glargine-aglr (Rezvoglar – Lilly), which was approved by the FDA as a biosimilar to the reference product Lantus in 2021 and received interchangeability status with Lantus in 2022, will become available in the US on April 1, 2023. It is the second biosimilar insulin product to be designated as interchangeable with Lantus; Semglee was the first. Rezvoglar did not receive interchangeability status with Lantus at the time of its initial approval because the manufacturer of Semglee had exclusivity for 12 months.

The FDA has approved glucagon nasal powder (Baqsimi – Lilly) for treatment of severe hypoglycemia in patients ≥4 years old with diabetes. Baqsimi is the first noninjectable glucagon formulation to become available in the US. Injectable glucagon emergency kits (GlucaGen Hypokit, and generic) have been available for years, but they require reconstitution of the lyophilized powder by the caregiver immediately before injection. An injectable glucagon formulation that does not require reconstitution was recently approved by the FDA (Gvoke) and is expected to become available later in 2019; it will be reviewed in a future issue.

The FDA has approved Fiasp (Novo Nordisk), a new formulation of insulin aspart, to improve glycemic control in adults with diabetes. Fiasp is described by the manufacturer as faster-acting than conventional insulin aspart (Novolog).

Lipid-lowering drugs should be taken indefinitely; when they are stopped, plasma lipoproteins return to pretreatment levels. HMG-CoA reductase inhibitors (statins) remain the drugs of choice for treatment of most patients who require lipid-lowering therapy.

In 2012, the FDA required manufacturers of HMG-CoA reductase inhibitors (statins) to add a warning to their labels about reports of increased blood glucose and glycosylated hemoglobin (HbA1c) levels. Since then, several new studies have been published.

The FDA has approved the MiniMed 530G (Medtronic), an insulin pump used in combination with a continuous glucose monitoring sensor (Enlite) that can stop delivery of insulin when interstitial glucose reaches a prespecified low level. It is the only sensoraugmented insulin pump available in the US with this capability.

Adults with a body mass index (BMI=kg/m²) of 25-<30 are considered overweight; those with a BMI of ≥30 are considered obese.

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).

Several large European observational studies published on-line this summer have raised questions about whether use of insulin glargine increases the risk of cancer.

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 FDA has issued an update (August 18, 2008; www.fda.gov) on occurrences of acute pancreatitis in patients with diabetes taking exenatide (Byetta – Amylin/Lilly). The latest update, which follows an FDA Alert in October 2007, reports 6 cases of hemorrhagic or necrotizing pancreatitis with 2 deaths in patients taking the drug. Whether pancreatitis occurs more often in patients taking exenatide than in patients with diabetes not taking exenatide is not clear.1

Given by subcutaneous injection, exenatide is a synthetic peptide that stimulates release of insulin from pancreatic beta cells.2 It is FDA-approved as adjunctive therapy in patients with type 2 diabetes. In addition to potentiating insulin release, exenatide slows gastric emptying, which may cause nausea and sometimes vomiting. The presenting symptoms of acute pancreatitis typically are nausea, vomiting and severe upper abdominal pain. Severe abdominal pain is not a usual side effect of exenatide. If pancreatitis is suspected in a patient taking exenatide, the drug should be discontinued promptly, and should not be restarted after recovery.

1. SR Ahmad and J Swann. Exenatide and rare adverse events. N Engl J Med 2008; 358:1970.
2. Exenatide (Byetta) for type 2 diabetes. Med Lett Drugs Ther 2005; 47:45.

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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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Colesevelam (Welchol - Daiichi Sankyo - Med Lett Drugs Ther 2000; 42:102), a bile-acid sequestrant used to lower LDL cholesterol, has been approved by the FDA as an adjunct to diet and exercise in the treatment of type 2 diabetes. In unpublished studies summarized in the package insert, patients with type 2 diabetes taking metformin (Glucophage, and others), a sulfonylurea or insulin (each as either monotherapy or in combination with other anti-diabetic agents) were given colesevelam 3800 mg per day or placebo; colesevelam significantly reduced glycosylated hemoglobin (A1c) by about 0.5% more than placebo in all three trials. The mechanism is unclear.

Colesevelam can cause constipation, nausea and dyspepsia, increase serum triglyceride concentrations, and interfere with absorption of other oral drugs. One month's treatment with Welchol obtained from drugstore.com would cost about $200. Medical Letter consultants are not enthusiastic about prescribing it for this indication.

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Losing even a small amount of weight and increasing physical activity can prevent some of the complications of obesity, particularly type 2 diabetes. Diet and exercise are the preferred methods for losing weight but are associated with high long-term failure rates. Drugs may help some patients, but all currently available drugs for weight reduction have drawbacks. Gastric surgery can produce marked weight loss in the severely obese, but long-term data on safety are limited.

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.

Sitagliptin (Januvia) and metformin (Glucophage, and others) are now available in a single tablet (Janumet - Merck) for treatment of type 2 diabetes. The combination is approved by the FDA for use in patients not adequately controlled by sitagliptin or meformin alone or in those already taking both drugs. Metformin is also available in combination with the thiazolidinediones pioglitazone and rosiglitazone and with the sulfonylureas glipizide and glyburide.

A variety of glucose monitoring devices have been used in an effort to reduce the hypoglycemia and wide glucose excursions that complicate insulin treatment of diabetes. Since the last Medical Letter issue reviewing such devices, more continuous glucose monitoring (CGM) systems have become available. Five devices available now, and two expected to be marketed soon, are listed in the table on page 14. The FDA has approved continuous glucose devices only for the observation of glucose trends.

Duetact (Takeda), a new fixed-dose combination of the thiazolidinedione pioglitazone (Actos) and the sulfonylurea glimepiride (Amaryl, and others), was recently approved by the FDA for treatment of type 2 diabetes. It is approved as an adjunct to diet and exercise to improve glycemic control in patients already taking pioglitazone and/or a sulfonylurea. Avandaryl, a combination of glimepiride and the thiazolidinedione rosiglitazone, was approved in 2006.

Sitagliptin phosphate (Januvia - Merck) is the first dipeptidyl-peptidase-4 (DPP-4) inhibitor to be marketed for treatment of type 2 diabetes. It has been approved by the FDA for oral use as monotherapy or in combination with metformin (Glucophage, and others), pioglitazone (Actos) or rosiglitazone (Avandia).

Insulin detemir (Levemir - Novo Nordisk) is the second long-acting basal insulin analog to be marketed in the US for treatment of both type 1 and type 2 diabetes. Detemir differs from human insulin by the elimination of the amino acid threonine in position B30 and the addition of a 14-carbon fatty acid chain at position B29. Insulin glargine (Lantus), the first long-acting insulin analog, has been available since 2001 and is usually given once daily.1 NPH insulin is an intermediate-acting basal insulin given twice daily. Basal insulins are usually combined with prandial doses of a rapid-acting insulin.

Insulin glulisine (Apidra - Sanofi Aventis) is the third rapid-acting insulin analog to be marketed in the US, following insulin lispro (Humalog) and insulin aspart (Novolog). All three have a more rapid onset and shorter duration of action than regular human insulin. Rapid-acting insulin analogs are generally taken immediately before meals and are usually combined with a long-acting basal insulin.

Patients may be asking about reports in the lay press that exenatide (Byetta - Med Lett Drugs Ther 2005; 47:45), a synthetic peptide that stimulates release of insulin from pancreatic beta cells, has been used by diabetics and non-diabetics to lose weight. Approved by the FDA to improve glycemic control in patients with type 2 diabetes not controlled by metformin, a sulfonylurea or both, it is given by subcutaneous injection before the morning and evening meals. In clinical trials, some diabetic patients treated with the drug lost weight. No data are available on use in non-diabetics. Exenatide slows gastric emptying and promotes satiety, which is presumably the mechanism of weight loss.

Patients should be warned that exenatide has some adverse effects. Hypoglycemia has occurred when the drug was added to a sulfonylurea but not when it was added to metformin. The risk of hypoglycemia in non-diabetics is unknown. Exenatide often causes nausea, which can be severe, and vomiting. Diarrhea can also occur. Because the drug slows gastric emptying, it can decrease the rate and extent of absorption of other drugs such as antibiotics and oral contraceptives; oral drugs should be taken at least one hour before exenatide.

Perhaps the greatest concern with off-label use of exenatide for weight loss is that 3 times the human dose given to pregnant animals slowed fetal growth and produced skeletal and other developmental abnormalities. The FDA classified it as category C (risk cannot be ruled out) for use during pregnancy. For diabetics and non-diabetics, pregnant or not, exenatide's long-term safety is unknown.

Coenzyme Q10, a fat-soluble antioxidant also known as ubidecarenone, ubiquinone and CoQ10, is marketed as a dietary supplement in the US, both as a single ingredient and in various combination products.

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).

Chromium is marketed as a dietary supplement, usually containing 20-500 mcg of a chromium salt. It has been promoted for weight loss, muscle building, and for prevention and treatment of diabetes, among other claims. As a dietary supplement, chromium can be sold without proof of efficacy or safety.

The FDA recently approved the use of atorvastatin (Lipitor) to reduce the risk of heart attack and stroke in patients without heart disease who have type 2 diabetes plus other risk factors, with or without hypercholesterolemia. The agency also approved the drug's use to reduce the risk of stroke in high-risk nondiabetic patients without heart disease, whether or not they have hypercholesterolemia. Similar indications were previously approved for simvastatin (Zocor).

Duloxetine hydrochloride (Cymbalta - Lilly), a selective serotonin and norepinephrine reuptake inhibitor (SNRI) available for treatment of depression, has also been approved by the FDA for treatment of neuropathic pain associated with diabetic peripheral neuropathy (DPN). Duloxetine is one of two drugs approved specifically for management of neuropathic pain due to diabetes; the other, pregabalin (Lyrica - Pfizer), will be marketed soon and will be reviewed in the next issue of The Medical Letter.

Exenatide injection (Byetta - Amylin/Lilly), a synthetic peptide that stimulates release of insulin from pancreatic beta cells, has been approved by the FDA as adjunctive therapy for patients with type 2 diabetes who have not achieved optimal glycemic control on metformin (Glucophage, and others), a sulfonylurea, such as glyburide (DiaBeta, and others), or both. Exenatide is not indicated for use with insulin.

Pramlintide acetate (Symlin - Amylin Pharmaceuticals), a synthetic analog of human amylin, has been approved by the FDA as adjunctive treatment for patients with type 1 or type 2 diabetes who inject insulin at mealtimes and have failed to achieve glucose control. Pramlintide is injected subcutaneously before meals.

Management of intermittent claudication, the most common symptom of peripheral arterial disease (PAD), involves both risk factor modification and symptomatic treatment (WR Hiatt, N Engl J Med 2001; 344:1608; RM Schainfeld, J Am Board Fam Pract 2001; 14:443).

Improved glucose meters and 2 sensing systems for continuous monitoring have become available for management of diabetes.

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).

An automatic, noninvasive, glucose-monitoring device (GlucoWatch Biographer) has been approved for marketing by the FDA. The manufacturer states that it is not meant to replace a regular blood glucose meter.

Lispro insulin (Humalog - Lilly), a synthetic insulin analog, has been approved for marketing by the US Food and Drug Administration. Prepared by recombinant DNA methods using E. coli, lispro differs from human insulin in having lysine and proline at positions 28 and 29 on the beta-chain, reversed from their natural position. The new drug has biologic effects similar to unmodified insulin, but is absorbed more rapidly after subcutaneous injection.

Most patients with diabetes mellitus now test their own blood glucose. In recent years, meters commercially available for self-testing have become smaller and easier to use.

The NovolinPen (Squibb - Novo) is a device that uses prefilled cartridges to inject semisynthetic human insulin (Medical Letter, 25:63, 1983). Three formulations are available: regular insulin (Novolin R PenFill), NPH insulin isophane (Novolin N PenFill) and a mixture of 70% NPH and 30% regular (Novolin 70/30 PenFill). The NovolinPen is advertised as more accurate, more convenient and less expensive than conventional syringes and needles. The same device is marketed in Canada as the Novolin-Pen II (Connaught Novo). (An earlier device is also available as the Novolin-Pen in Canada and the NovoPen in the USA.)

Most patients with diabetes mellitus now test their own blood glucose. In recent years, meters commercially available for self-testing have become smaller in size and easier to use and less expensive.