Insulin

Overview & Types

Insulin is the hormone used to control blood glucose. Preparations vary by onset/duration:

• Rapid-acting: (e.g., Lispro, Aspart) — onset 5–15 min, used at meal times.
• Short-acting: (Regular insulin) — onset ~30 min.
• Intermediate-acting: (NPH) — onset 1–2 hrs, duration ~12–18 hrs.
• Long-acting: (Glargine, Detemir, Degludec) — once daily, basal control.
• Premixed: Combination of rapid/short + intermediate for convenience.

Uses

• Treatment of Type 1 diabetes (mandatory lifelong)
• Used in Type 2 diabetes when oral agents are insufficient
• Management of diabetic emergencies (e.g., hyperglycaemia, DKA under medical care)
• Perioperative/gestational diabetes under specialist guidance

Dosage & Administration

• Individualized dosing — based on weight, diet, glucose readings and physician plan.
• Most insulins are given subcutaneously (abdomen, thigh, buttock, upper arm).
• Rapid-acting: given immediately before or after meals; long-acting: once daily (same time each day).
• Premixed: typically twice daily before meals.

Important: Follow your diabetes care team's insulin regimen exactly. Do not change dose without medical advice.

Possible Side Effects

• Hypoglycaemia: (low blood sugar) — sweating, tremor, hunger, confusion, fainting (most serious risk).
• Injection site reactions — redness, lipodystrophy (rotate sites).
• Weight gain (can occur with insulin therapy).
• Allergic reactions (rare).

Precautions & Warnings

• Monitor blood glucose regularly (SMBG or CGM) to adjust dose and avoid hypoglycaemia.
• Be cautious with renal or hepatic impairment — dosing adjustments may be needed.
• Carry a source of fast-acting carbohydrate (glucose tablets, juice) for hypoglycaemia.
• Inform healthcare providers about insulin type and doses during illness, travel, or surgery.

Drug Interactions

• Certain medicines (e.g., steroids, some diuretics, sympathomimetics) can raise blood glucose, requiring higher insulin doses.
• Other drugs (e.g., beta-blockers, some oral hypoglycaemics) may mask hypoglycaemia symptoms or increase risk.
• Alcohol can increase risk of delayed hypoglycaemia.

Storage & Handling

• Unopened insulin: store in refrigerator (2–8°C) — do not freeze.
• In-use pens/vials: may be kept at room temperature (check manufacturer guidance) and used for specified days.
• Protect from direct sunlight and heat. Check expiry date and discard used needles safely in sharps container.

Always follow the leaflet and manufacturer's instructions for storage and cartridge/pen handling.

FAQs

• Can insulin be mixed? Some insulins (e.g., short-acting with NPH) can be mixed in one syringe — only as instructed by your clinician and when compatible.
• Will I need insulin forever? Type 1: yes. Type 2: may be temporary or long-term depending on disease progression.
• How to treat hypoglycaemia? Give 15–20 g fast-acting carbs (glucose tablets or 150–200 ml fruit juice), recheck after 15 minutes, repeat if needed; seek help if unconscious.

When to Seek Help

Seek urgent care for severe hypoglycaemia (loss of consciousness, seizures), diabetic ketoacidosis symptoms (nausea, vomiting, abdominal pain, deep rapid breathing), or persistent high glucose despite treatment.

Disclaimer

This page is for educational purposes only and does not replace medical advice. Insulin dosing and type must be prescribed and supervised by qualified healthcare professionals. Follow your diabetes care team's instructions carefully.