Indications
Isophane Human Insulin (also called NPH insulin) is an intermediate acting insulin used to control blood sugar in people with type 1 diabetes and in people with type 2 diabetes who need insulin. It provides background (basal) insulin between meals and overnight. It is often supplied premixed with Regular Human Insulin (for example 30/70 mixtures) to cover both meals and background needs.
How It Works
Insulin helps the body’s cells take up sugar from the blood and stops the liver releasing too much glucose. In Isophane Insulin, human insulin is combined with a protein called protamine, which makes it cloudy and slows its release from under the skin. It starts working in about 1 to 2 hours, peaks at about 4 to 12 hours and lasts up to about 16 to 24 hours.
Dosage and Administration
The dose is set individually by your doctor and is usually given once or twice a day, so use it exactly as prescribed. Before each injection, gently roll the vial or pen between your palms and tip it up and down about 10 times until the liquid is evenly cloudy; do not shake hard. Inject under the skin of the abdomen, thigh, buttock or upper arm, changing the spot each time within the same area. Isophane Insulin must never be given into a vein. Never share insulin pens or needles.
Interactions
- Other diabetes medicines, alcohol, ACE inhibitors, some antidepressants and salicylates can increase the sugar lowering effect.
- Steroids, thyroid hormones, some diuretics, oral contraceptives and some antipsychotics can raise blood sugar and increase insulin needs.
- Beta blockers may hide the warning signs of low blood sugar.
- Pioglitazone with insulin can increase the risk of heart failure.
Contraindications
- Low blood sugar (hypoglycaemia) at the time of injection.
- Allergy to human insulin, protamine or any ingredient.
- Intravenous use.
Side Effects
The most common side effect is low blood sugar, which can happen several hours after injection, including at night. Signs include sweating, shaking, hunger, fast heartbeat, headache, nightmares, confusion or irritability. Redness, swelling or itching at the injection site and lumps under the skin from repeated use of the same spot can occur. Weight gain and temporary blurred vision or ankle swelling may occur when starting treatment.
If you have signs of low blood sugar, take glucose, sugar or a sugary drink straight away, then a snack. Get urgent medical help if the person is confused, unable to swallow, has a fit or loses consciousness (do not give anything by mouth; a glucagon injection or hospital treatment is needed), or if there is a serious allergic reaction.
Pregnancy and Lactation
Human insulin, including Isophane Insulin, is a standard treatment for diabetes in pregnancy and is safe for the baby. Insulin needs change during pregnancy and after delivery, so blood sugar must be checked closely. It is safe during breastfeeding; doses may need adjusting.
Precautions and Warnings
- Check blood sugar regularly, including before bed, especially when changing dose, diet or activity, or when ill.
- Always carry a source of glucose and a diabetes identification card.
- Do not drive if your blood sugar is low; check before driving.
- Never change insulin type, brand or strength without medical advice.
- Do not use if the insulin stays clumped or has particles after mixing.
Overdose
Too much insulin causes low blood sugar, which can be prolonged with this longer acting insulin and can lead to fits, unconsciousness and brain damage. Treat mild cases with glucose or sugar by mouth followed by food; severe cases need emergency medical help with glucagon or intravenous glucose and observation.
Therapeutic Class
Antidiabetic; intermediate acting human insulin (NPH).
Storage
Store unopened insulin in a refrigerator at 2 to 8°C; do not freeze. The vial or pen in use can be kept below 25 to 30°C, away from heat and light, for the period stated on the pack (usually 4 to 6 weeks). Keep out of the reach of children.
Prepared by the Oshud Alo team from standard drug references. For information only; always follow your doctor's advice.