Humulin N 100 iu/ml 10 vial

Humulin N – NPH Human Insulin 100 IU/ml by Eli Lilly

What is Humulin N?

Humulin N is an intermediate-acting NPH (Neutral Protamine Hagedorn) human insulin manufactured by Eli Lilly using rDNA technology. NPH insulin combines regular human insulin with protamine — a protein that slows absorption and extends duration to 12–18 hours. Unlike long-acting analogues (Lantus, Levemir, Tresiba), NPH has a pronounced peak at 4–10 hours — which can cause hypoglycaemia if meals are missed or delayed. Available as a 10 ml vial for syringe use, Humulin N is widely used in Bangladesh as a cost-effective basal insulin, both alone and in combination with Humulin R for complete basal-bolus coverage using two vials.

Generic Name & Composition

Each ml contains 100 IU of isophane human insulin (NPH, rDNA origin). NPH is formed by combining regular human insulin with protamine sulphate and zinc, crystallising the insulin into a suspension absorbed more slowly than soluble insulin. Result: onset 1–2 hours, peak 4–10 hours, duration 12–18 hours. NPH is a cloudy white suspension that must be gently rolled and inverted before each use.

Indications

• Type 1 diabetes mellitus — basal insulin in twice-daily or once-daily regimens
• Type 2 diabetes mellitus — basal insulin, typically once or twice daily
• Combined with Humulin R (regular) in syringe-based basal-bolus regimens
• First-line basal insulin in gestational diabetes and diabetes in pregnancy (WHO-recommended)

How It Works — Mechanism of Action

After subcutaneous injection and resuspension, NPH crystals dissolve slowly as protamine is released, delivering human insulin over 12–18 hours. The pronounced peak at 4–10 hours provides intermediate coverage but requires careful meal timing to avoid hypoglycaemia at peak. Absorbed insulin activates receptors: GLUT-4 mediated glucose uptake, suppression of hepatic glucose output, glycogen synthesis.

Dosage & Administration

Regimen: Once daily at bedtime (Type 2) or twice daily (morning + bedtime, Type 1 or intensive Type 2). Starting dose (Type 2): 10 IU at bedtime; titrate by 2 IU every 3 days. Mixing: Draw Humulin R first (clear), then Humulin N. Vial use: Roll 10 times, invert 10 times until uniform milky suspension. Draw required dose with U-100 syringe. Inject subcutaneously. Rotate sites.

Side Effects

Very common: Hypoglycaemia — particularly at peak (4–10 hrs). Nocturnal hypoglycaemia is a significant concern with bedtime NPH dosing.

Common: Injection site reactions, lipohypertrophy, weight gain.

Uncommon: Lipoatrophy, peripheral oedema, visual changes at initiation.

Rare: Protamine hypersensitivity reactions, anaphylaxis.

Drug Interactions

Increase hypoglycaemia risk: Oral antidiabetics, GLP-1 agonists, SGLT-2 inhibitors, ACE inhibitors, ARBs, MAO inhibitors, salicylates, alcohol.

Reduce insulin effect: Corticosteroids, glucagon, thyroid hormones, thiazides, sympathomimetics, oral contraceptives.

Caution: Beta-blockers mask hypoglycaemia symptoms.

Contraindications

• Hypersensitivity to human insulin, protamine, or any excipient
• Active hypoglycaemia
• MUST NOT be given intravenously — protamine causes adverse IV reactions

Pregnancy & Lactation

Pregnancy: NPH has the longest safety record of all insulins in pregnancy. WHO recommends NPH (or detemir) as first-line basal insulin in gestational and pre-existing diabetes in pregnancy. Lactation: Safe during breastfeeding; not orally bioavailable.

Precautions & Warnings

• Resuspend before every injection: Roll 10 times, invert 10 times. NPH is a suspension — unresuspended crystals cause inaccurate dosing.
• Pronounced peak: 4–10 hour peak creates a hypoglycaemia window — patients must not skip or delay meals at peak time.
• Never administer IV: NPH contains protamine — unsafe for intravenous use.
• Switching to long-acting analogues: Consider 20% dose reduction when switching from NPH to glargine or degludec.

Overdose

Prolonged hypoglycaemia (12–18 hrs). Mild: oral glucose. Severe: IV dextrose or IM glucagon. Sustained monitoring required throughout duration of action.

Storage Instructions

• Unopened: 2–8°C. Do not freeze. Protect from light.
• In-use vial: Below 30°C or refrigerated. Use within 28 days.
• Never freeze — freezing destroys protamine crystal structure.

Frequently Asked Questions (FAQs)

Q1: What is the difference between Humulin N and Lantus (glargine)?
Humulin N (NPH): onset 1–2 hrs, peak 4–10 hrs, duration 12–18 hrs — pronounced peak, higher nocturnal hypoglycaemia risk. Lantus (glargine): onset 2–4 hrs, virtually peakless, duration ~24 hrs — flatter profile, lower hypoglycaemia. NPH is less expensive; Lantus/Tresiba offer better predictability.

Q2: Can Humulin N and Humulin R be mixed in the same syringe?
Yes. Draw Humulin R (clear) first, then Humulin N (cloudy). Standard technique: draw air for N → draw air for R → draw R → draw N. Premixed 70/30 (Humulin 70/30) is also available for fixed-ratio convenience.

Q3: Why must Humulin N be resuspended before injection?
NPH is a protamine-insulin crystal suspension. Crystals settle between uses. Without rolling and inverting (10 times each), dose accuracy is lost — you may inject mostly diluent or mostly crystals.

Q4: Who manufactures Humulin N?
Eli Lilly and Company (Indianapolis, USA). Humulin N was one of the first rDNA insulins launched commercially, in 1982.

⚕ Medical Disclaimer: For educational purposes only. Humulin N is Rx-only. Consult your diabetologist before changing insulin therapy. DiabetesStore.com.bd is a licensed online pharmacy.