Insulin: Indications, Types and Side Effects

Insulin: Indications, Types, and Side Effects

Indications for Insulin Use

Insulin is primarily indicated for managing blood glucose levels in patients with:

1. Type 1 Diabetes Mellitus: Essential due to the absence of endogenous insulin production.
2. Type 2 Diabetes Mellitus: Used when oral medications and lifestyle changes are insufficient to achieve glycemic control.
3. Gestational Diabetes: For pregnant women unable to maintain blood glucose levels with diet alone.
4. Diabetic Ketoacidosis (DKA): A critical condition requiring intravenous insulin.
5. Hyperosmolar Hyperglycemic State (HHS): Severe hyperglycemia managed with insulin.
6. Perioperative Management: In diabetic patients undergoing surgery to maintain glucose stability.
7. Pancreatic Disorders: Conditions like chronic pancreatitis or pancreatectomy where insulin production is impaired.

Types of Insulin

Insulin types are classified based on their onset, peak, and duration of action:

1. Rapid-Acting Insulin
   • Examples: Aspart (Novolog), Lispro (Humalog), Glulisine (Apidra)
   • Onset: 10-30 minutes
   • Peak: 30-90 minutes
   • Duration: 3-5 hours
   • Use: Taken just before or after meals to control postprandial glucose.
2. Short-Acting Insulin
   • Example: Regular insulin (Humulin R, Novolin R)
   • Onset: 30-60 minutes
   • Peak: 2-4 hours
   • Duration: 5-8 hours
   • Use: Pre-meal bolus or in emergency settings like DKA.
3. Intermediate-Acting Insulin
   • Example: NPH (Humulin N, Novolin N)
   • Onset: 1-2 hours
   • Peak: 4-12 hours
   • Duration: 12-18 hours
   • Use: Basal insulin for twice-daily dosing.
4. Long-Acting Insulin
   • Examples: Glargine (Lantus, Toujeo), Detemir (Levemir)
   • Onset: 1-2 hours
   • Peak: Minimal peak (steady effect)
   • Duration: 24 hours or longer
   • Use: Provides consistent basal insulin.
5. Ultra-Long-Acting Insulin
   • Example: Degludec (Tresiba)
   • Onset: 1 hour
   • Peak: None
   • Duration: 42+ hours
   • Use: Basal insulin with flexible dosing.
6. Premixed Insulins
   • Examples: 70/30 (70% NPH, 30% Regular), 75/25 (75% intermediate Lispro, 25% rapid Lispro)
   • Onset/Peak/Duration: Combination of the components’ profiles.
   • Use: Simplifies dosing by combining basal and bolus insulin.

Side Effects of Insulin

1. Common Side Effects
   • Hypoglycemia: Symptoms include sweating, shakiness, confusion, dizziness, and, if severe, loss of consciousness.
   • Weight Gain: Due to increased glucose uptake and storage.
   • Injection Site Reactions: Redness, swelling, or pain.
   • Lipodystrophy: Thickening (lipohypertrophy) or thinning (lipoatrophy) of subcutaneous fat at injection sites.
2. Rare Side Effects
   • Allergic Reactions: Rash, itching, or severe anaphylaxis.
   • Edema: Fluid retention leading to swelling.
   • Hypokalemia: Insulin shifts potassium into cells, potentially causing low potassium levels.
   • Insulin Resistance: Gradual loss of response to insulin requiring dose adjustment.

Key Considerations

• Dose Adjustment: Based on blood glucose levels, diet, physical activity, and illness.
• Storage: Keep insulin refrigerated before use and at room temperature when in use for comfort during injection.
• Patient Education: Teach proper injection technique, site rotation, and hypoglycemia management.