1. Clinical Overview
Human Premix (100IU) is a sterile, white, lyophilized powder containing 100 International Units (IU) of highly purified human insulin isophane (NPH) suspension. It is an intermediate-acting insulin used for the management of diabetes mellitus. The 'premix' formulation combines a rapid-acting insulin analog (commonly insulin aspart) with a protamine-bound intermediate-acting insulin (NPH) to provide both immediate postprandial and sustained basal glycemic control. In the Indian context, it is a critical tool for simplifying insulin regimens, improving compliance, and managing type 2 diabetes where post-meal glucose spikes are a significant concern.
| Onset | Duration | Bioavailability |
|---|---|---|
| Onset: 15-30 minutes (due to rapid-acting component). | Duration: Up to 24 hours (primarily due to the NPH component). | Approximately 55-77% via subcutaneous route; varies by injection site, depth, and local blood flow. |
2. Mechanism of Action
Human Premix insulin mimics endogenous insulin physiology. The rapid-acting component (e.g., insulin aspart) provides a quick onset to control postprandial glucose rise by facilitating rapid cellular uptake of glucose. The intermediate-acting NPH component provides a prolonged basal insulin level to suppress hepatic glucose production between meals and overnight. Overall, it regulates carbohydrate, fat, and protein metabolism by binding to the insulin receptor on target cells (muscle, liver, adipose).
3. Indications & Uses
- Type 2 Diabetes Mellitus inadequately controlled on oral antidiabetic drugs (OADs).
- Type 1 Diabetes Mellitus as part of a basal-bolus regimen (though less common than separate injections).
4. Dosage & Administration
Adult Dosage: Highly individualized. Typically started at 0.2-0.4 IU/kg/day or 10 IU once or twice daily (usually before breakfast and/or dinner). Dose is titrated based on self-monitored blood glucose (SMBG), targeting pre-meal and post-meal values. Common regimens: Biphasic insulin aspart 30 (30% aspart, 70% NPH) administered twice daily.
Administration: FOR SUBCUTANEOUS USE ONLY. 1. Gently roll the vial/pen between palms to resuspend until it appears uniformly cloudy/milky. DO NOT SHAKE. 2. Inject into abdominal wall, thigh, buttock, or upper arm. Rotate sites. 3. Administer immediately before a meal (within 15 minutes). 4. Use a U-100 insulin syringe or pen device. 5. Do not mix with other insulins in the same syringe unless specified.
5. Side Effects
Common side effects may include:
- Hypoglycemia (most common)
- Injection site reactions (pain, redness, itching, lipodystrophy)
- Weight gain
- Peripheral edema (especially on initiation).
6. Drug Interactions
| Drug | Effect | Severity |
|---|---|---|
| Oral Hypoglycemics (Sulfonylureas, Meglitinides) | Additive hypoglycemic effect; risk of severe hypoglycemia. | Major |
| Corticosteroids (e.g., Prednisolone) | Antagonize insulin effect; increase insulin requirements. | Major |
| Beta-blockers (e.g., Propranolol) | Mask tachycardia warning signs of hypoglycemia; may potentiate or impair recovery. | Moderate |
| Thiazide Diuretics (e.g., Hydrochlorothiazide) | May cause hyperglycemia, increasing insulin needs. | Moderate |
| ACE Inhibitors (e.g., Ramipril) | May enhance hypoglycemic effect. | Moderate |
| Alcohol | Potentiates hypoglycemia; can cause delayed hypoglycemia. | Major |
| MAO Inhibitors, Anabolic Steroids | Increase hypoglycemic effect. | Moderate |
7. Patient Counselling
- DO check blood sugar levels regularly as advised.
- DO inject immediately BEFORE a major meal.
- DO rotate injection sites to prevent lipodystrophy.
- DO carry a fast-acting sugar source (glucose tablets) at all times.
- DO store unopened vials/pens in refrigerator (2-8°C).
- DON'T shake the vial/pen vigorously; roll gently to mix.
- DON'T inject into muscle or a vein.
- DON'T skip meals after injection.
- DON'T use if the suspension appears clear or has clumps.
- DON'T share pens or syringes.
8. Toxicology & Storage
Overdose: Profound and prolonged hypoglycemia: sweating, tremor, tachycardia, anxiety, hunger, confusion, drowsiness, speech difficulty, seizures, coma, and death if untreated.
Storage: Unopened (Refrigerated): Store at 2°C to 8°C in original carton. Do not freeze. Keep away from freezer compartment and direct heat/light. In-use (Room Temperature): Once punctured, the vial can be kept at room temperature (below 30°C) for up to 28 days. Protect from direct heat and sunlight. Do not refrigerate in-use product. Discard after 28 days even if solution remains. Do not use if frozen, discolored, or contains particles.