Insulin: Uses, Dosage, Side Effects, and More
1. Drug Name
Generic Name: Insulin
Brand Name(s):
- Pakistan: Mixtard, Novorapid, Lantus
- India: Huminsulin, Novomix, Basalog
- United States: Humalog, Novolin, Lantus
- United Kingdom: Humulin, Insuman, Abasaglar
2. Pharmacological Class
Class: Antidiabetic agent
Subclass: Hormone
3. Mechanism of Action
Insulin facilitates cellular uptake of glucose, regulates blood sugar levels, and inhibits hepatic glucose production. It also promotes storage of glucose as glycogen in the liver and muscle cells.
4. Indications
Primary Indications:
- Type 1 diabetes mellitus
- Type 2 diabetes mellitus when oral medications are ineffective
Off-label Uses:
- Gestational diabetes
- Hyperkalemia (in combination with glucose)
5. Dosage and Administration
Standard Dosage:
- Dosage is individualized based on blood glucose monitoring results, type of insulin used, and patient needs.
- Typical starting dose: 0.4 to 1.0 units/kg/day divided into multiple doses.
Route of Administration: Subcutaneous injection, intravenous (for certain types only)
Special Populations:
- Pediatric: Dosing is weight-based and adjusted according to blood glucose levels.
- Geriatric: Initiate at lower doses due to increased risk of hypoglycemia.
6. Pharmacokinetics
Absorption: Varies with the type of insulin, site of injection, and other factors.
Distribution: Distributed widely throughout the body, primarily affecting liver, muscle, and adipose tissue.
Metabolism: Metabolized primarily in the liver and kidneys.
Excretion: Excreted mainly by the kidneys.
Half-life: Varies with the type of insulin; typically between 4-6 minutes for endogenous insulin.
7. Contraindications
Insulin is contraindicated in patients with:
- Hypersensitivity to insulin or any of its components
- Hypoglycemia
8. Warnings and Precautions
Use caution in patients with:
- Renal or hepatic impairment
- Elderly patients (increased risk of hypoglycemia)
- Hypoglycemia unawareness
Monitor blood glucose levels regularly to avoid hypoglycemia or hyperglycemia.
9. Side Effects
Common Side Effects:
- Hypoglycemia
- Injection site reactions
- Weight gain
Serious Side Effects:
- Severe hypoglycemia
- Allergic reactions
- Hypokalemia
10. Drug Interactions
Major Interactions:
- Beta-blockers (can mask hypoglycemia symptoms)
- Thiazolidinediones (increased risk of heart failure)
Moderate Interactions:
- Diuretics (can affect blood glucose levels)
Minor Interactions:
- Alcohol (can increase or decrease blood glucose levels)
11. Pregnancy and Lactation
Pregnancy Category: B
Breastfeeding Considerations: Insulin is generally considered safe during breastfeeding, but blood glucose levels should be monitored closely.
12. Patient Counseling Information
Key Points for Patients:
- Take insulin exactly as prescribed.
- Regularly monitor blood glucose levels and keep track of results.
- Recognize symptoms of hypoglycemia and how to treat it.
Administration Tips:
- Rotate injection sites to reduce the risk of lipodystrophy.
- Store insulin in the refrigerator and avoid extreme temperatures.