Lantus (Insulin Glargine)

Lantus (insulin glargine) is a long‑acting insulin analog used to provide basal insulin support in the management of diabetes.

• Type 1 diabetes mellitus: maintains basal glucose control throughout day and night, reducing hyperglycemia episodes.
• Type 2 diabetes mellitus: complements oral antidiabetic agents or other insulins to achieve target glycemic levels.
• Pediatric diabetes: offers stable basal insulin for children with type 1 diabetes, facilitating growth‑appropriate glucose management.

• Insulin glargine binds to insulin receptors on muscle, adipose and hepatic cells, mimicking endogenous insulin. Its altered amino‑acid sequence promotes self‑association into micro‑precipitates after subcutaneous injection, resulting in a slow, steady release of insulin over approximately 24 hours. This prolonged activity enhances glucose uptake, suppresses hepatic glucose production, and provides continuous basal insulin coverage without pronounced peaks. The prolonged action helps maintain stable plasma insulin concentrations between meals and overnight.

The most frequently reported adverse reactions with insulin glargine relate to its pharmacologic action and injection site.

Common Side Effects

• Hypoglycemia: low blood glucose episodes, especially if meals are missed or dose is excessive.
• Injection site reactions: redness, swelling, or itching at the administration site.
• Weight gain: gradual increase in body weight associated with improved glycemic control.
• Edema: mild fluid retention, often transient.

Serious or Rare Side Effects

• Severe hypoglycemia: profound low glucose requiring assistance.
• Anaphylactic reaction: rare systemic allergic response that may include hives, airway swelling, or shock.
• Insulin antibody formation: immune response that can alter insulin efficacy.
• Lipohypertrophy necrosis: severe localized tissue damage at injection sites.

When using insulin glargine, several precautions should be observed to ensure safe and effective therapy.

• Blood glucose monitoring: check levels regularly to adjust dose as needed.
• Dose adjustments with steroids: increase dose when patients start systemic corticosteroids.
• Renal or hepatic impairment: use caution and consider lower starting doses.
• Hypoglycemia unawareness: avoid in patients who cannot perceive low glucose symptoms.
• Pregnancy and lactation: category B; discuss risks and benefits with healthcare provider.
• Store at 2-8°C: keep refrigerated, protect from light, do not freeze or shake.

Insulin glargine may interact with other medicines, affecting glucose control or insulin action.

Major Interactions (Avoid)

• Concomitant use with other insulins or rapid‑acting insulin analogs: risk of severe hypoglycemia.
• Sulfonylureas and meglitinides: additive glucose‑lowering effect, may cause hypoglycemia.
• Beta‑blockers: can mask hypoglycemia symptoms, complicating detection.

Moderate Interactions (Monitor Closely)

• Systemic corticosteroids: increase insulin resistance, may require higher insulin dose.
• Thiazide diuretics: may raise blood glucose, necessitating dose adjustment.
• ACE inhibitors and ARBs: can affect potassium balance and renal function, influencing insulin requirements.
• Antidepressants (e.g., SSRIs): may alter appetite and glucose metabolism, requiring monitoring.