Links to guidance
Refer to Grampian Guidelines and SIGN 116 for further information.
- Grampian Guidelines for the Management of Diabetes Mellitus (2011)
- Grampian Guidelines for the Management of Diabetes
- SIGN 116: Management of diabetes
- NPSA Rapid Response Report: Safer administration of insulin
In this section
There are a large and confusing number of insulin preparations available. If patients are satisfied with their treatment and achieving satisfactory control in the absence of hypoglycaemia, no modification of their regimen is required.
Patients should not be changed from the insulin that they are currently receiving without advice from a specialist or a clinician with the appropriate skills and expertise.
Most insulin currently in use is biosynthetically manufactured of human sequence or analogues with altered pharmacokinetic properties. Many patients prefer the rapid-acting analogues/mixtures for convenience.
A few patients prefer to use animal derived insulin in the belief that use of human sequence insulin may cause loss of awareness of hypoglycaemia. Although such a conviction is quite widespread, carefully conducted scientific studies have consistently failed to provide evidence to support this hypothesis.
Refer to NPSA Safer administration of insulin Rapid Response Report for further information.
- "units" must never be abbreviated when prescribing or recording administration of insulin.
- Insulin must always be measured or administered using an insulin syringe or commercial insulin pen device.
- Insulin should be prescribed by brand name in full to avoid errors.
- If possible confirm insulin details with the patient when prescribing, administering or dispensing insulin.
- Humalog®/Humalog® Mix: extra care should be taken when prescribing, administering or dispensing these insulins due to the potential for error and confusion between the different preparations.
Insulins are most conveniently classified by duration of action as shown in the table below.
Rapid-acting insulins Humalog®, NovoRapid®, Apirda® and mixtures Humalog® Mix25 or Mix50, NovoMix® 30 should usually be injected subcutaneously immediately before eating.
Other insulins should be injected subcutaneously 30 minutes before eating.
Intermediate- and long-acting insulins are usually injected subcutaneously once daily at the same time of day.
|Duration of action||Insulin (Brand)|
Humalog®, NovoRapid®, Apidra®
Short-acting soluble insulin
Intermediate-acting isophane insulin (contains protamine)
Long-acting (contains crystalline zinc)
Patients are normally commenced on human insulin or an insulin analogue, in either a twice-daily or a multiple-injection regimen. The choice of the initial regimen and subsequently modifications should be made in consultation with the patient, taking due regard of the patient's occupation and lifestyle. The precise insulin formulation may be determined by the patient's preferred insulin delivery device. Most patients prefer to use pen devices.
Single daily injections are increasingly used, alongside metformin and sulfonylurea tablets, in elderly patients with inadequate control on oral therapy alone. This approach may provide adequate control for a time but the possibility of progression to two or more injections daily must be borne in mind.
Once-daily regimens do not usually result in good glycaemic control, and are not the preferred approach in Type 1 diabetes or in younger patients with Type 2 diabetes requiring insulin. Such a regimen may be appropriate for patients where the therapeutic goal is only to prevent ketosis or suppress symptomatic hyperglycaemia and where there are practical problems with insulin delivery, or particular concern over the risks of nocturnal hypoglycaemia. Elderly patients living alone and patients requiring injections to be given by a district nurse may fall into this category.
Once-daily bedtime intermediate acting isophane insulin (NPH) is the basal insulin of choice.
Long-acting basal analogue insulins may be considered if there are particular concerns regarding hypoglycaemic risk but evidence suggests that this only rarely confers benefit for the substantial additional cost incurred. These insulins may also be preferred where a patient requires a district nurse to visit in the morning to administer insulin.
This is still a commonly used regimen and suitable for patients starting on insulin who are reluctant to take a multiple injection regimen or unconvinced by its potential flexibility. A combination of short- and intermediate-acting insulins (i.e a pre-mixed preparation) is taken before breakfast and before the evening meal. Twice-daily human pre-mixed insulin may be a safer choice than analogue preparations in patients requiring insulin administration by district nurse to allow enough time to prepare a meal after insulin administration.
This arrangement, most commonly involving up to four injections a day has the main advantage of increased flexibility with regard to exercise, meal timing and meal size. It is most likely to work effectively in a well-motivated patient, prepared to do regular blood testing and to engage in self-adjustment of dosage.
The majority use a rapid-acting insulin analogue or soluble insulin before each meal, (bolus injections) and an intermediate- or long-acting insulin usually before the evening meal, mid-evening or at bedtime to provide background cover (basal injection), i.e basal bolus regimen.
Some patients on the basal-bolus insulin regimes achieve better results when using basal insulin twice-daily.
Continuous subcutaneous insulin infusion (insulin pump therapy) requires a considerable amount of patient engagement and self-management as patients are required to monitor blood glucose and regulate insulin dosage serially throughout the day: refer to Grampian Guidelines for the Management of Diabetes for further information.
- All patients who are using them should be instructed in the safe disposal of lancets, single-use syringes and needles.
- Some insulins are available as a vial which requires administration via an insulin syringe.
- Injection devices, are however, more convenient for patients. Several such devices are available. Care should be taken to ensure the patient uses the correct pen device for their insulin.
- Disposable pre-loaded devices are also available and are commonly used.
- Choice of injection device depends on the particular needs of the individual patient, taking into account lifestyle, age, preference and capabilities.