Insulin Isophane/nph + Human Insulin/soluble Insulin is a two-staged combination of soluble human insulin (rapid-acting) and insulin isophane/NPH (intermediate-acting). It is used to manage blood glucose levels in type 1 and type 2 diabetes mellitus. The soluble component provides a quick initial glucose-lowering effect to manage blood sugar spikes experienced post-meal. The NPH component provides a prolonged baseline effect to control fasting and inter-meal glucose. Together, they deliver both around meals (prandial) and basal insulin coverage in a single injection.

Insulin Isophane/nph + Human Insulin/soluble Insulin is an insulin product combining two distinct types of insulin in a fixed ratio. The common ratio available for this product could be 30/70, 50/50 or 25/75 based on what your doctor recommends for your condition. Insulin Isophane/nph + Human Insulin/soluble Insulin is designed to more closely simulate the body's natural physiological insulin release pattern than a single insulin preparation alone.

Soluble human insulin is structurally similar to endogenous insulin. After the injection is delivered subcutaneously (between the fatty tissue and muscle), it begins to act within 30 minutes, peaks at 1 to 3 hours, and stays for a duration of 6 to 8 hours, covering mealtime glucose spikes. Insulin isophane (NPH — Neutral Protamine Hagedorn) is a microcrystalline suspension of soluble insulin mixed with protamine at a neutral pH. This complex dissolves slowly at the injection site, producing a delayed onset of 1.5–2 hours. The peak comes at 4 to 12 hours, stays for a duration of 16 to 24 hours, providing inter-meal and overnight basal insulin coverage.

Because the two insulins are pre-combined, this preparation reduces the number of daily injections and simplifies the insulin regimen. It is extremely useful for people who need both prandial and basal coverage and would otherwise need separate injections of each.

Type 1 Diabetes Mellitus

Provides complete basal and prandial insulin replacement.

Type 2 Diabetes Mellitus

Used when oral antidiabetic agents are insufficient to provide the desired glycaemic control.

Gestational Diabetes

May be used after a doctor’s recommendation when lifestyle measures are inadequate.

• Both fast-acting and long-acting types of insulin are combined in a single injection, lowering the frequency of daily injections.

• Soluble insulin effectively controls post-meal blood glucose spikes.

• NPH insulin maintains basal glucose levels between meals and overnight.

• Simplifies insulin regimens, improving treatment adherence, especially in people diagnosed with type 2 diabetes.

• Available in multiple ratio formulations, allowing people to choose from what suits their condition better based on their doctor’s recommendation.

Common

• Hypoglycaemia (low blood sugar), the most frequent adverse effect that may present as tremors, sweating, hunger, and palpitations (pounding of the heart)
• Redness, swelling, and lipodystrophy (loss of fat) on the injection site due to repeated injections at the same site
• Weight gain

Uncommon

• Oedema (swelling due to fluid buildup), especially in the beginning or after a significant dose increase
• Temporary change in vision due to rapid changes in blood glucose
• Localised allergic skin reactions

Serious requiring immediate attention

• Severe hypoglycaemia, which may present as confusion, seizure, or loss of consciousness
• Systemic allergic reaction, which may present as a generalised rash, angioedema (swelling in deep tissues), and anaphylaxis
• Hypokalaemia (low potassium), especially in patients on concurrent diuretics

Administered by subcutaneous injection only in the abdomen, thigh, or upper arm. It should never be administered intravenously (in the veins) or intramuscularly (in the muscles) for routine use. Gently roll the vial or pen before use to resuspend the NPH component. Never shake vigorously. Inject 15–30 minutes before a meal. Rotate injection sites at every dose to prevent lipodystrophy. Your dose is strictly individualised by your doctor and must not be altered without medical guidance.

In healthy individuals, pancreatic beta cells release insulin continuously in small amounts (basal secretion) and in larger amounts after meals (prandial secretion). Insulin binds to the transmembrane tyrosine kinase (an insulin receptor) present on target cells in skeletal muscle, adipose tissue, and the liver.

When insulin binds to its receptor on the cell surface, it triggers a chain reaction inside the cell (IRS-1 → PI3K → Akt pathway). In muscle and fat cells, it causes glucose transporter proteins to move from inside the cell to the cell surface, opening the door for glucose to enter from the bloodstream. In the liver, it prevents the breakdown of stored glycogen into glucose and the production of new glucose from amino acids and other sources. Both actions reduce the amount of glucose the liver releases into the blood.

The soluble and NPH components of the injection activate this same mechanism, just at different times. The soluble insulin does it quickly to handle the post-meal glucose rise, while NPH does it slowly and steadily in the background to keep glucose levels stable between meals and overnight.

The soluble insulin component dissolves readily after subcutaneous injection and is absorbed rapidly into the bloodstream, producing a short, sharp insulin peak that handles post-meal glucose excursions, mimicking the natural prandial insulin spike.

The NPH component is an insoluble microcrystalline suspension of insulin-protamine complexes. At the injection site, tissue proteases gradually digest the protamine-insulin lattice, releasing free insulin molecules slowly over many hours. This sustained, controlled release produces a flat, prolonged insulin profile that suppresses hepatic glucose output between meals and overnight, closely mimicking physiological basal insulin secretion. The combination in a single injection thus delivers both mealtime and background glucose control simultaneously.

• Alcohol (SEVERE): Inhibits hepatic gluconeogenesis (crucial for blood sugar maintenance), masking early hypoglycaemia symptoms (tachycardia, sweating) and prolonging or worsening hypoglycaemic episodes.

• High-glycaemic meals: Consuming unexpectedly large amounts of carbohydrates relative to the insulin dose can cause post-meal hyperglycaemia.

Oral antidiabetics (sulfonylureas)

CAUTION

Increases the risk of hypoglycaemia

Beta-blockers

CAUTION

Masks tachycardia (high BP), which is a key warning sign of hypoglycaemia

Corticosteroids / Thiazide diuretics

CAUTION

Works opposite to insulin, raising blood glucose

MAO inhibitors

CAUTION

May add on to insulin's glucose-lowering effect, increasing hypoglycaemia risk

ACE inhibitors

CAUTION

May enhance insulin sensitivity

• Renal impairment: Insulin is cleared by the kidneys. If the renal function is impaired, insulin action gets prolonged, increasing the risk of hypoglycaemia.

• Hepatic impairment: Low hepatic glucose production and impaired insulin metabolism increase hypoglycaemia risk.

• Hypokalaemia: Insulin drives potassium into cells. This increases the risk of hypokalemia in patients with already-low potassium.

• Heart failure: Insulin-induced fluid retention may worsen fluid overload in heart failure patients.

• Hypothyroidism / Adrenal insufficiency: Both conditions increase insulin sensitivity and hypoglycaemia risk.

An insulin overdose can result in hypoglycaemia. Mild hypoglycaemia can result in tremors, sweating, hunger, or palpitations and can be treated with fast-acting carbohydrates (glucose tablets or fruit juice). Severe hypoglycaemia can cause confusion, seizures, loss of consciousness, or even coma; therefore requires intravenous glucose (50% dextrose) or intramuscular glucagon injection. Seek emergency medical attention immediately. Do not wait for symptoms to worsen.

Because Insulin Isophane/nph + Human Insulin/soluble Insulin is taken before meals, a missed dose should be handled carefully. If you remember, take the dose as directed before starting your meal. If you have already eaten or significant time has passed, skip the missed dose and do not double the next dose. Monitor your blood glucose more frequently after a missed dose. Consult your doctor for specific guidance as insulin regimens are highly individualised.