Insulin Glargine

Insulin glargine is a long-acting basal insulin analog used for background glucose control.

It provides a relatively flat, 24-hour insulin profile with minimal peak.

→ Insulin Therapy

Glargine binds to the insulin receptor (tyrosine kinase receptor).

This activates:

• IRS signaling pathways
• PI3K/Akt cascade
• GLUT4 translocation in muscle and adipose tissue

Primary basal function:

• Suppresses hepatic gluconeogenesis
• Provides steady background insulin

Glargine differs from human insulin by:

• Replacement of asparagine at A21 with glycine
• Addition of two arginine residues at B31 and B32

These modifications:

• Shift isoelectric point
• Make insulin soluble in acidic solution (in vial)
• Cause precipitation in neutral subcutaneous tissue

After injection:

• Microprecipitates form in subcutaneous tissue
• Slow, continuous release of insulin monomers

This creates a prolonged, relatively peakless effect.

Onset:

• ~1–2 hours

Peak:

• Minimal or no pronounced peak

Duration:

• ~24 hours (dose-dependent)

Compared to:

• NPH → no pronounced peak, lower nocturnal hypoglycemia
• Detemir → longer duration in most patients
• Degludec → shorter duration

Typically given once daily.

• Basal insulin in Type 1 Diabetes
• Basal insulin in Type 2 Diabetes

Often combined with:

• Rapid-acting insulin (basal-bolus regimen)
• Metformin
• GLP-1 Receptor Agonists
• SGLT2 Inhibitors

• Once-daily dosing
• Reduced nocturnal hypoglycemia compared to NPH
• More stable glucose control
• Predictable pharmacokinetics

• Hypoglycemia
• Weight gain
• Injection site reactions

Hypoglycemia risk increases with:

• Excess dosing
• Reduced caloric intake
• Increased activity

NPH:

• Has peak
• Higher hypoglycemia risk

Detemir:

• Albumin-binding
• May require twice-daily dosing

Degludec:

• Ultra-long duration (>42 hours)
• Most stable pharmacokinetic profile

Glargine:

• 24-hour duration
• Flat profile
• Once-daily dosing
• Widely used

• Long-acting basal insulin
• Precipitates in subcutaneous tissue
• Minimal peak
• Once-daily dosing
• Lower nocturnal hypoglycemia than NPH
• Foundation of basal-bolus therapy

• Insulin Therapy
• Detemir
• Degludec
• NPH
• Diabetes Pharmacology