Generic Biphasic Isophane Insulin (75/25 or 70/30)

Insulin Isophane/NPH (75%) + Human Insulin/Soluble Insulin (25%)
Price: ₹180 - ₹300 per vial
Mfr: Various (e.g., Sun Pharmaceutical Industries Ltd., Lupin Ltd., Torrent Pharmaceuticals Ltd.) | Form: Vial (10 mL)

📋 Clinical Overview

A biphasic isophane insulin injection, also known as biphasic human insulin or 75/25 premixed insulin. It is a sterile suspension containing 75% Insulin Isophane (NPH, an intermediate-acting insulin) and 25% Human Insulin (regular, soluble, short-acting insulin) in a single vial or cartridge. This combination provides both a rapid onset to cover postprandial glucose rise and a prolonged duration to provide basal insulin coverage, simplifying the regimen for patients requiring both meal-time and basal insulin.

💊 Dosage & Administration

Adult: Highly individualized. Typically initiated at 0.2-0.5 units/kg/day, divided into 2 doses (pre-breakfast and pre-dinner). The total daily dose is often split as 2/3 in the morning and 1/3 in the evening, but must be titrated based on blood glucose monitoring. Usual maintenance range: 0.5-1.0 units/kg/day.

Note: For SUBCUTANEOUS injection only. Administer 30-45 minutes before a meal. Rotate injection sites (abdomen, thigh, buttocks, upper arm) to prevent lipodystrophy. Gently roll the vial/pen to resuspend; do not shake. Inspect visually; it should be uniformly cloudy/milky. Do not use if clear, discolored, or contains particles. Use appropriate insulin syringe (U-100) or delivery device.

⚠️ Contraindications

  • Hypoglycemia
  • Hypersensitivity to insulin isophane, human insulin, protamine, or any excipient (e.g., metacresol, phenol)

🔬 Mechanism of Action

Insulin is the principal hormone required for proper glucose utilization. It regulates carbohydrate, lipid, and protein metabolism by promoting cellular uptake of glucose (especially in muscle and adipose tissue), inhibiting hepatic glucose production (glycogenolysis and gluconeogenesis), and promoting glycogen, lipid, and protein synthesis.

🤕 Side Effects

  • Hypoglycemia (most common)
  • Injection site reactions (pain, redness, itching, swelling)
  • Lipodystrophy (lipoatrophy or lipohypertrophy at injection sites)
  • Weight gain
  • Peripheral edema (especially upon initiation)

🤰 Special Populations

Pregnancy: Pregnancy Category B (US FDA). Insulin is the drug of choice for glycemic control in pregnant women with pre-existing or gestational diabetes. Requirements may decrease in first trimester and increase significantly in second/third trimesters. Close monitoring and dose adjustments are mandatory.

Driving: Caution required. Patients must check blood glucose before driving and regularly on long journeys. Must be aware that hypoglycemia can impair cognitive and motor functions. Should always carry a fast-acting carbohydrate source (glucose tablets) in the vehicle.

🔄 Drug Interactions

Oral Hypoglycemic Agents (Sulfonylureas, Meglitinides)Additive hypoglycemic effect, increased risk of hypoglycemia.Major
Corticosteroids (e.g., Prednisolone, Dexamethasone)Antagonize insulin effect, cause hyperglycemia, requiring dose increase.Major
Beta-blockers (e.g., Propranolol)May mask tachycardia symptoms of hypoglycemia, potentiate hypoglycemia, and impair recovery.Moderate
Thiazide Diuretics (e.g., Hydrochlorothiazide)May cause hyperglycemia, increasing insulin requirements.Moderate
ACE Inhibitors (e.g., Ramipril)May enhance insulin sensitivity, increasing hypoglycemia risk.Moderate
AlcoholPotentiates hypoglycemic effect and can cause delayed hypoglycemia, especially in fasting state.Major
MAO Inhibitors, Anabolic SteroidsIncrease hypoglycemic effect.Moderate
Thyroid Hormones, Somatropin, DanazolIncrease blood glucose, requiring higher insulin doses.Moderate

🔁 Alternatives to Generic Biphasic Isophane Insulin (75/25 or 70/30)

Same composition (Insulin Isophane/NPH (75%) + Human Insulin/Soluble Insulin (25%)), different brands:

Mixtard 30/70 (Note: This is the common 70/30 ratio, but 75/25 is also marketed under similar names; specific 75/25 brands are less common but available) Huminsulin 30/70 (70/30 ratio. 75/25 specific formulations may be available as 'Huminsulin NPH' and 'Regular' separately for mixing.) Wosulin 30/70 (70/30 premixed) Insugen 30/70 (70/30 premixed)