Lantus Risks, Warnings, and Complications

RISK OF INFECTION WITH SHARED EQUIPMENT: Never share your insulin equipment, including the Lantus (insulin glargine) vial or pen, with others or use other people’s equipment, even if the needle and syringe are changed. Doing so can result in serious infections.

HYPOGLYCEMIA (LOW BLOOD SUGAR) OR HYPERGLYCEMIA (HIGH BLOOD SUGAR): Changes in your insulin regimen can lead to changes in your blood glucose levels. Make sure you understand the insulin type and strength, manufacturer, injection site and method of administration. Check labels before injecting insulin to ensure you are taking the right type and dose. Your doctor will monitor you carefully during dosage adjustments. 

Severe hypoglycemia can be life-threatening and may require treatment with concentrated intravenous glucose. Follow your doctor’s recommendations about how often you should monitor glucose levels, especially after changes in insulin dose, addition or discontinuation of other drugs to treat your diabetes, or changes in dietary and physical activity patterns, which can affect glucose metabolism. People with renal or hepatic impairment are at a higher risk of severe symptomatic hypoglycemia compared to those with normal renal or hepatic function. If you have liver or kidney disease, talk to your doctor about how often you should monitor blood sugar levels.

ALLERGIC REACTIONS: There are reports of severe, life-threatening allergic reactions, including anaphylaxis (throat closing), after taking Lantus (insulin glargine) products. Stop using Lantus and seek emergency medical care if you develop a skin rash, hives, itching, swelling, hoarseness, wheezing, or difficulty breathing or swallowing.

LOCALIZED CUTANEOUS AMYLOIDOSIS AND LIPODYSTROPHY: Localized cutaneous amyloidosis, also called insulin-derived amyloidosis or an insulin ball, is a subcutaneous collection of amyloid protein under the skin surface that can develop at an injection site where you give yourself repeated insulin injections. Lipodystrophy is an area of destruction of fat cells. Many patients find insulin injections to be less painful at sites of localized cutaneous amyloidosis and lipodystrophy and therefore inject the medicine into the insulin ball instead of a new injection site. 

However, injecting Lantus (insulin glargine) into an area of localized cutaneous amyloidosis or lipodystrophy (fat accumulation or fat loss) can lead to decreased absorption of the drug, which can result in hyperglycemia (high blood sugar). 

Suddenly switching the injection site to an unaffected area can lead to increased absorption of the drug and hypoglycemia (low blood sugar). 

You should rotate (change) insulin injection sites regularly and avoid using the same site more often than once every 1-2 weeks. 

HYPOKALEMIA: Some people using Lantus (insulin glargine) can develop hypokalemia (low serum potassium concentrations). Your doctor will monitor potassium levels if you are at risk of this complication. Keep all your medical and laboratory appointments while using Lantus.

FLUID RETENTION AND HEART FAILURE: Using insulin glargine and oral diabetes medications called thiazolidinediones (TZDs) such as pioglitazone and rosiglitazone can increase the risk of fluid retention and heart failure. Call your doctor immediately if you develop swelling in the ankles or feet or sudden weight gain. Signs and symptoms of heart failure may require discontinuation or dose reduction of Lantus (insulin glargine).

COMPARISON WITH NPH INSULIN: Lantus (insulin glargine) is a long-acting insulin. NPH insulin is an intermediate acting insulin. 

Studies on insulin comparator groups have compared Lantus (insulin glargine) and NPH insulin treated patients. They have found that people in the insulin glargine group have as effective glucose control as the NPH insulin group. In addition, there are fewer episodes of low blood sugar (hypoglycemia) with insulin glargine compared to the NPH insulin treatment groups.

People on long-term treatment with insulin products are at a risk of immunogenicity or the formation of antibodies against insulin. The presence of such insulin antibodies can affect insulin serum concentrations and increase or decrease insulin efficiency, requiring an adjustment in the insulin dose. Clinical trials have shown that both Lantus and NPH insulin increase the levels of insulin antibodies at a similar rate.