About insulin

Insulin is a hormone that is made naturally in your body, in the pancreas. It helps to control the levels of glucose (sugar) in your blood.

If your body does not make enough insulin to meet its needs, or if it does not use the insulin it makes effectively, it results in the condition called diabetes mellitus (sugar diabetes). People with diabetes mellitus need treatment to control the amount of sugar in their blood. This is because good control of blood sugar levels reduces the risk of complications in diabetes.

Insulin is manufactured to closely resemble natural human insulin. It can also be derived from pork or beef but this is rarely used nowadays. Insulin cannot be taken by mouth, as it is destroyed by the digestive juices in your digestive system. It is therefore given by an injection under the skin. Insulin may come in a vial to be injected with a separate syringe, in a cartridge to be used with an injection device (pen), in a pre-filled injection device, or it can be given continuously by a pump.

There are different types of insulin available which are classified according to how quickly and for how long they work. Short-acting or soluble insulin works quickly and is usually injected just before meals. Intermediate and long-acting insulins take longer to work and the effects last longer. Biphasic insulin products contain both a short-acting and an intermediate or long-acting insulin.

There are many different products available. The type of insulin you are prescribed will be tailored to your needs. It is very important that you use the same product each time unless your doctor or diabetes nurse tells you otherwise.

Before using insulin

Before using insulin make sure your doctor or pharmacist knows:

• If you are pregnant, trying for a baby or breast-feeding.
• If you have liver or kidney problems.
• If you have ever had an allergic reaction to any medicine.
• If you are taking any other medicines, including those available to buy without a prescription, herbal and complementary medicines.

How to use insulin

• Before starting this treatment, read the manufacturer's printed information leaflet from inside the pack as well as the information you have been given by your doctor or diabetes clinic.
• Use your insulin exactly as your doctor has told you. Your doctor or diabetes nurse will show you how to inject yourself with insulin. It is usually injected into your upper arms, thigh, buttocks or abdomen.
• Insulin doses are referred to in terms of units. Make sure you know how much to use - ask your doctor or nurse if you are unsure.
• Your treatment will be tailored to your needs. It may consist of one or more types of insulin and the amounts you use will be carefully chosen to suit you.
• You will be told when to inject your doses, as different types of insulins are given at different times in relation to food. It is important that you inject your doses when you have been advised to. Do not miss out any of your doses of insulin.
• Some types of insulin require mixing before you withdraw a dose. This is done by rolling the bottle slowly between your hands or by tipping the bottle upside down and then gently rotating it. Do not shake insulin because it will froth or bubbles will form in the liquid and this will cause you to measure an incorrect dose.

Getting the most from your treatment

• It is important that you keep your regular doctor's and clinic appointments. This is so that your progress can be monitored.
• You must test for the amount of sugar in your blood or urine regularly to make sure that you are using the right dose of insulin. Your doctor or diabetes nurse will show you how to do this and you will also be told how to use the results of the test.
• Check with your doctor before taking up any new physical exercise as this will have an effect on your blood sugar levels and you may need to check your levels more regularly.
• Check with your doctor if you develop an infection or a high temperature, as you may need to adjust your dose if you are unwell.
• It is important that you regularly change the site where you inject the insulin on your body.This is to help prevent skin problems and difficulties in injecting.
• Each time you collect your prescription, check you have been given the right type of insulin. Getting the wrong insulin by mistake may lead to your blood glucose being too high or too low. If anything looks different from what you have had before, ask your pharmacist to check the prescription for you. If you have been given an insulin 'Passport' or an insulin ID card, show this to your pharmacist to confirm the type of insulin you use.
• Make sure you know what it feels like if your blood sugar is too low. This is known as hypoglycaemia or a 'hypo'. The first signs of hypoglycaemia are: feeling shaky or anxious, sweating, looking pale, feeling hungry, having palpitations (a feeling that your heart is pounding), and feeling dizzy. If these happen you should eat or drink something containing sugar or have a snack, straightaway.
• Keep to recommended alcohol limits. Taking insulin and alcohol will affect the control of your blood sugar. Do not drink alcohol on an empty stomach as this can cause severe hypoglycaemia.
• If you are due to have an operation or dental treatment, you should tell the person carrying out the treatment that you are diabetic and using insulin. If you go into hospital and you are unable to keep or give your own insulin, don't be afraid to ask the hospital staff for your insulin when it is needed.
• If you are a driver, you must let the Driver and Vehicle Licensing Agency (DVLA) know that you are being treated with insulin. Take special care if you drive on long journeys. You should check your blood sugar level before you start your journey and then every two hours during the journey. If you feel your blood sugar is low, stop the car in a safe place, eat or drink something sugary, and then wait at least fifteen minutes before you continue on your journey.
• There may be times when your blood sugar levels are too high. This is known as hyperglycaemia. This can occur if you eat more than normal, or if you have a fever, or if you take too low a dose of insulin. The signs of hyperglycaemia are: feeling sleepy, looking flushed, having a fruity smell on your breath, feeling a need to pass urine more often, having no appetite, and feeling unusually thirsty. If you experience these symptoms, you should contact your doctor or diabetes nurse straight away.
• If you have been given advice by your doctor about changes to your diet, stopping smoking or taking regular exercise, it is important for you to follow the advice you have been given.

Can insulin cause problems?

Insulin has few side-effects but you may feel some lumpiness at the site of the injection. Varying the places you inject will help to avoid this from happening.

How to store insulin

• Keep all medicines out of the reach and sight of children.
• Store your unopened insulin in a refrigerator until you are ready to use it. Do not freeze insulin.
• Once your insulin is in use, you can keep it for four weeks at room temperature, as long as this is below 25°C and it is kept away from direct heat and sunlight.
• Any vials, pre-filled pens and cartridges must be discarded 28 days after being first used.

Important information about all medicines