If tablet treatments do not control your blood glucose you will be advised to move to the injectable treatments or if you have Type 1 diabetes you will be started on insulin from diagnosis.
This is the only treatment available for the management of Type 1 diabetes.
It is used, often in combination with tablets, particularly metformin, in the treatment of Type 2 diabetes where tablet treatment alone has failed to control the blood glucose level.
Insulin is the hormone which is released from the pancreas when the sugar supply to the body is increased after eating.
It lowers the blood glucose very effectively. In non-diabetic people, the body will sense the blood glucose level and release just the right amount of insulin to keep the glucose level steady. If we give the insulin by injection, we need to monitor the blood glucose level ourselves and adjust the dose accordingly.
Originally, insulin was extracted from animal pancreas, but all insulin is now made synthetically. This has allowed us to change the structure slightly to either stretch or shorten the length of time it works after injection. There are many brands of insulin available on the market, but they can be put into broad groups which differ in terms of duration of action.
Short acting insulins (last 0 to 4 hours)
- Humulin S
Intermediate acting insulins
- Humulin I
Long acting (background) insulins
- Tresiba u100 and u200
- Toujeo u300
Premixed insulins (biphasic insulins)
These are a combination of intermediate and short acting insulins. The number associated with the name is the percentage or fraction of the total dose which is quick acting insulin.
- Humulin M3
- Insuman Comb 25 and 50
- Humalog Mix 25
- Humalog Mix 50
Further information about insulin can be found at www.diabetes.org.uk
There are 3 basic ways in which the daily insulin can be given.
Basal bolus insulin
This is the best way to give insulin if there are no practical obstacles. It uses a background insulin, usually given at night, together with injections of short acting insulin before meals. The advantages are:
- The background insulin allows overnight glucose control and should deliver a morning blood glucose result within target.
- The premeal doses of short acting insulin can be given at times to suit an individual’s mealtimes.
- The doses of premeal insulin can be adjusted according to circumstances.
- The premeal doses can be adjusted according to the carbohydrate content of the meal with use of carbohydrate counting and a smart meter
The obvious downside of the basal bolus regimen is that it involves 4 injections of insulin per day, and the individual must be fully involved in measuring the blood glucose level and in making decisions on the doses and timing of the insulin doses. People who do not like the intrusion of multiple injections and testing in their lives, or cannot manage these aspects would be considered for other forms of insulin.
Premixed or biphasic insulins
These are formulations of insulin which are broadly designed to last 12 hours after injection. They are therefore given twice a day.
The advantages are:
- Easy to administer and only 2 injections per day
- Available in a variety of pen injector devices
The disadvantages are:
- They are premixed and last 12 hours, so it is difficult to adjust the dose according to changing routines
- The proportion of quick to slow acting insulin is fixed and does not vary greatly between the different preparations, so they may not be right for some individuals.
However, this way of giving insulin is suitable for many, particularly those with Type 2 diabetes who are not so sensitive to insulin, and can be discussed as an option.
We sometimes give only one injection a day of long acting (background) insulin at night. This is mainly used as a treatment option in people with type 2 diabetes as it allows some insulin to be given together with a variety of tablet treatments or other injectable treatment. This option would be discussed with you as part of your treatment plan, but would usually be given with a number of other treatments.
There are a number of individuals who prefer, for personal reasons, to continue using pig or beef insulin. These insulins are still available to prescribe, but as the market is very small, the options are extremely limited.
We would not recommend the use of animal insulin as it holds no benefit over preparations in current use and severely limits choices of preparation and injection devices. However, in respect for the wishes of the individual, this can be discussed.
This is ONLY an option FOR PEOPLE WITH TYPE 1 DIABETES.
This is available on the NHS for people with type 1 diabetes who cannot achieve good control of their diabetes with multiple daily injections of insulin. The insulin is short acting which is given under the skin as a continuous delivery via the pump. The pump can be programmed to deliver different doses throughout the day, and therefore breaks up the total amount given in 24 hours into many different segments. It is important to recognise that the pump does not take away the responsibility for management of diabetes. The individual still needs to measure their blood glucose and adjust the dose of insulin.
These are the second variety of injectable treatments currently available.They are only used in the treatment of Type 2 diabetes.
Currently available formulations:
- Byetta (twice daily)
- Bydureon (once weekly)
- Lixumia (once daily)
- VIctoza (once daily)
- Trulicity (once weekly)
- Semaglutide (Ozempic) (once weekly)
Glucagon-like peptide-1 (GLP-1) is one of a number of hormones produced by the intestine in response to the nutritional status of the individual. It is produced in response to food intake, and has the effect of reducing appetite, slowing the stomach, increasing insulin production from the pancreas, and reducing the levels of hormones which increase blood sugar. When produced by the body it only stays in the system for a few minutes, but by changing the formulation very slightly, the duration of action has been prolonged to stop breakdown and these are now available as treatments for diabetes.
Given the list of actions, GLP-1 analogues are an ideal treatment for Type 2 diabetes (they are limited value in type 1 diabetes because the effects on insulin production cannot take place). They are given under the skin in the same way as insulin. The original product, Byetta, was short acting and had to be given twice a day. Subsequent products have extended the duration of action up to a week.
The side effects of these agents are mainly on the gastrointestinal system. Because they slow the stomach, they can cause abdominal discomfort and nausea. However, this usually passes within a few days of starting, and for that reason we start with a low dose and increase later as tolerated. Diarrhoea can occasionally be a problem, but is unusual as stomach emptying is delayed.
The advantage of these treatments is that they lower blood glucose effectively, and on their own, they leave the glucose sensing mechanisms intact, so the blood glucose does not fall too low (hypos). They may also help with weight loss. However, not everybody responds well to these, but they are commonly used, if only for a trial period. They may also be used in combination with all the tablet treatments (except ‘gliptins’ which are working on the same pathway) and may be used together with insulin. The particular preparation used will be discussed with your diabetes team and will depend upon your needs and circumstances.
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