Diabetes mellitus Transfer of patients with Type 2 diabetes to insulin (includes combination treatment)

Each person must be individually assessed. Indication for commencing insulin therapy will be based on one or a combination of symptoms and biochemistry results

Clinical condition or situation to which this protocol applies

This group protocol applies to the commencement of treatment of subcutaneous insulin in patients with Type 2 diabetes currently receiving treatment with oral agents.

• Diabetes specialist nurses working within the Northumbria Diabetes Team will use this group protocol to prescribe insulin in patients with Type 2 diabetes. 
• Practice nurses working within primary care who have been trained to transfer patients from oral agents to insulin will use this group protocol.

The decision to transfer patients to insulin treatment will be based on a number of criteria

• Diagnosis of Type 2 diabetes. 
• HbA1c above 8.0 (reference range 4.5-6.1) 
• Severe symptoms of polyuria, polydipsia, nocturia, recurrent infections, balanitis, thrush. 
• Patient currently receiving treatment with maximum oral agents (for those on Metformin this dose may be up to the level to which the patient can tolerate the medication). 
• Lifestyle changes (food & exercise) maximised.

All patients with Type 2 diabetes transferring to insulin must have been following the protocol for patients with Type 2 diabetes expected to require insulin.

Maximum dose of oral agents

• Glibenclamide 15mg od (->10mg morning, 5mg at tea-time) 
• Tolbutamide ig bd Gliclazide 160mg bd 
• Glimepiride 6mg od (not usually used as 'standard' in Northumbria) 
• Rapiglinide 4mg qds (not usually used as 'standard' in Northumbria) 
• Metformin 1g tds (patients with abnormal renal and/or liver function refer to prescribing OHAs protocol) 
• Rosiglitazone 4mg od (combined with max. sulphonylurea, 8mg od combined with maximum tolerance Metfonnin. 
• Acarbose 100mg tds

Insulin therapy can be commenced at a number of sites including the patients home, (this may be in nursing or residential care premises) on a hospital ward, within the Diabetes Centre or in primary care.

Starting insulin therapy in the patients home - points to consider

• Safe if the person is not vomiting, not severely acidotic and has no medical condition requiring admission. 
• If the patient is vomiting and unwell admission to hospital will be necessary. 
• Experienced nursing and medical support is available for supervision of the patient, either at the hospital or primary care. 
• Patients who commence insulin on a hospital ward will have had an assessment by the relevant physician. The first dose of subcutaneous insulin will be administered on the ward. 
• NB: Consider psychological or social problems, which may affect coping in the community.

Exclusion

• Patients diagnosed with Type 1 Diabetes requiring insulin treatment. 
• Children and young adults up to the age of 19 years. Supervision and commencement of insulin therapy is by the paediatric / young adult team using appropriate protocol. 
• Patients with concurrent medical problems requiring hospital admission.

Characteristics of staff authorised to use this protocol

• Diabetes specialist nurses will be Registered General Nurses and also registered with the UKCC. Some nurses will be educated to diploma or degree level, and some may have a community qualification. 
• Nurses will take primary responsibility following the decision to commence insulin for supervising the starting and dose adjustment of insulin. 
• Practice nurses and senior community nurses who have been identified to supervise the transfer of patients to insulin within primary care will also work to this protocol. This will include community nurses supervising patients self injecting insulin at home, or administering insulin to patients who cannot self-administer, using dose adjustment guidelines. 
• Senior Dieticians trained to Diabetes Advisor level may also adjust insulin.

Staff training

• All nurses including community and practice nurses and dieticians using this protocol should have specialist diabetes training. This is normally provided within the district diabetes service as in-service training. Regular up-dates should be a part of multi-disciplinary in-service training programme. Accredited courses available: ENB 928, UNN Diabetes in the Community.

Insulin prescribing

All medicines included in this protocol are insulin and have "Pharmacy" status. The following insulins will be used: 

• Commencement is usually on Isophane Insulatard (Insulatard for pens) at a small dose given by subcutaneous injection. 
• Insulin Su bd (6u. For a pen which delivers in multiples of 2u.) if the random laboratory blood glucose level is below l5mmol 
• Insulin 10 units bd if the blood glucose is l5mmol/L or above.

Reduction of oral agents

Oral agents will be gradually reduced as the insulin dose is increased to minimise the risk of blood glucose levels rising further during the transfer to insulin treatment.

If Metformin oral medication is planned to be stopped, this is stopped completely on the first day on which insulin treatment is commenced.

Sulphonylureas

On the first day of insulin therapy the dose will be halved, this will be continued for a further 48 hours as long as the blood glucose levels remain above 10 mmol/L and on the fourth day of insulin treatment this dose will halved again and continued for a further 48 hours provided the blood glucose levels remain above 10 mmol/L.

After a further 48 hours sulphonylurea treatment will be either halved or stopped, the insulin will continue to increased using this protocol.

• Insulin is increased by 2units bd until blood glucose readings are under 10 mmol/L. 
• Insulin can be increased by 4 units bd if blood glucose level remains above L7mmol after 48hrs of insulin therapy

If daily insulin requirements increase to 20u in a single dose of intermediate acting insulin e.g. Insulatard, soluble insulin is introduced to the regime as follows:

• Introduction of a pre-mixed Biphasic insulin (Human Mixtard) Start with Mixtard 30.
• A mixture of soluble insulin and insulin zinc suspension (Human Actrapid and Human Monotard). This will not initially prescribed for patients commencing insulin but is here for completeness for those patients already using tI regime.

Usually 2/3 of the total daily dose is required at the morning injection and 1/3 in the evening. The dose ratio should commence with 1/3 soluble 2/3 zinc suspension. 

• Or a Basal Bolus regime to allow greater flexibility of meal timing, meal sizes and content. This is a combination pre-prandial soluble (Actrapid) insulin, given with a background of medium / long acting insulin taken at bedtime using Insulatard or Ultratard insulin. (Background insulin is between 40% - 50% of total daily requirements; the dose is adjusted according to the fasting glucose result.

Supervision is maintained until blood glucose levels are in the target range. The aim is to reduce all blood glucose result below 10mmol within the first six weeks of insulin therapy. The long-term range is between 4 and 8mmol for young patients and between 4 and 10 mmol for patients over 70 years, or for those with special medical needs.

Increase each insulin by 2-4 units at each injection up to a maximum of 10 units increase per day. Insulin is adjusted according to blood glucose levels, dietary needs and symptoms.

Combination therapy 

Some patients will have insulin therapy in combination with oral agents. (see: 'A stepped approach to Type 2 diabetes')

Patients with Type 2 diabetes have greater insulin resistance. Patients who do not reach their target levels of glucose control need to be discussed with the Physician and ideally a multi-disciplinary discussion should take place whic includes a dietician. In these patients combination therapy will be considered.

Rationale 1
Insulin and Metformin

• This is the most likely combination of insulin and an oral agent. Use in obese patients, with a BMI above 30 
• Where excessive weight gain is anticipated for patients commencing insulin therapy Metformin medication will be continued up to a maximum dose of 1g tds (provided this dose is tolerated by the patients without GI symptoms)
• Patients must have an assessment prior to commencing insulin which establishes that their dietary adherence exercise are optimised.
• Studies have suggested that combination treatment with Metformin can reduce prescribed insulin doses by 1/3 and improve glycaemic control.

NOTE: All contraindications for the use of Metformin should be considered

Patients with Type 2 diabetes established on insulin treatment can be considered for the introduction of Metformin to their regime:

• Patients who have been transferred to insulin from oral agents previously who remain with an HbAlc level above 8.0%. 
• Patients who have increased their total BMI since commencing insulin treatment by e.g 5 Kg. 
• U+Es and normal LFT results should be available within previous 6 months to commencing Metformin treatment. 
• Diet and exercise should be assessed and optimised prior to commencing new treatment. 
• Commence Metformin 500mg tds, this will need to be introduced slowly to reduce the risk of GI symptoms (discuss). 
• If glycaemic control improves and blood glucose levels fall below 6 mmol/L insulin can be reduced 2u bd, a reviewed. 
• If glycaemic control is still sub-optimal established by HbA1c 8 or above after 6 weeks on Metformin 500mg tds this can be increased to 1gm tds (maximum)

Rationale 2
Type 2 diabetes for patients to continue on oral hypoglycaemic agents and once daily subcutaneous insulin - (possibly transferring to BD insulin)

• This regime is relatively new and should be considered when the HbA1c levels deteriorate beyond 7.5% and the patient is on maximum oral hypoglycaemic agents. 
• Lifestyle issues should be discussed and optimised. It is thought that improved glycaemic control with the addition of OD insulin could preserve pancreatic function for longer and allow oral hypoglycaemic agents to continue for up to 2 years.

Insulin Adjustment for patients on sulphonylureas - update

Management 

• Diet and exercise optimised 
• Establish patient is on maximum oral hypoglycaemic agents and taking them as prescribed. 
• Establish blood glucose levels and any patterns of hyperglycaemia i.e. during the day or during the night. 
• Commence on Human Insulatard Insulin 6u daily. 
  • This injection will be given pre-breakfast if hyperglycaemia occurs during the day. 
  • This injection will be given prior to evening meal if hyperglycaemia occurs during the night, this is established fro] pre-bed and pre-breakfast blood glucose levels. 
• Increase insulin 2u daily post prandial BM <10, FPG <8mmol/L. 
• If OD insulin and oral agents does not achieve diurnal BM profiles as above consider BD Insulatard. (Commence second dose at 6u and increase as before) 
• If BD insulin dose is >40 units total in 24 hours, discuss with Physician whether sulphonylurea treatment should continue- a temporary withdrawal of sulphonylurea may be considered to determine if sulphonylurea having an therapeutic effect. 
• Improved control with combination treatment can sometimes reduce insulin resistance and improve pancreatic reserve. In these instances it may be possible to temporarily stop insulin. 
• Note: Rosiglitazone is not licensed for use in combination with insulin.

When insulin is prescribed twice daily, this is given before breakfast, and before the evening meal. 'The two injections should be not less that 7 hours apart. The aim should be to accommodate the patients preferred routine as much r possible, and allow for some flexibility with the timing of meals.

Consider Biphasic insulin immediately for young fit people with good understanding. Biphasic insulin initially prescribed for newly diagnosed children, usually human Mixtard 30 (see paediatric protocol).

A pen injection device is considered for patients who: 

• Would gain independence for self injection 
• At the patients request for ease of administration 
• Have a physical problem with sight or dexterity which would inhibit correct drawing up of insulin into a syringe

Dietary advice: 

• All patients will have had a full dietary assessment prior to the decision for insulin treatment being made. 
• Lifestyle (food and exercise) changes made pre-insulin should be reinforced to attain good HbA1c results with excessive weight gain using insulin therapy.

Patient Education: 

• Systematic ongoing diabetes education is commenced, this will include teaching adjusting the insulin dose according to the blood glucose levels, dietary intake and planned activity, to enable future self management. 
• Blood glucose monitoring is carried out before each meal and measured by either BM 1-44 test strips for visual monitoring, or a blood glucose meter with the appropriate test strips. 
• Appendix 1: Education checklist.

Criteria for a patient to make contact: 

• If blood glucose falls to 6mmol or below during the first three weeks of treatment (provided this has not already be identified) 
• If blood glucose levels rises to l7mmol or above on two consecutive tests (providing previous results were 10mm or below)

Adverse drug reactions: 

• All suspected adverse reactions to insulin therapy should be reported to a doctor within 3 working days unless the patient is systemically affected when immediate medical attention is required. 
• Commencement and any change in treatment including a change in insulin type should be documented on the home visiting record. This may also be used for audit purposes. 
• Hypoglycaemia: this is an anticipated side effect of insulin therapy. Patients receive education, which enables the to learn how to recognise their symptoms, and self-administer appropriate treatment. Family and carers will all receive education to enable them to deal with unrecognised hypoglycaemia.

Supplementary prescribing: 

Actrapid insulin and Ketostix is provided for illness management and Glucagen injection kit for severe hypoglycaemia with appropriate training to patient and carer. (Appendix: education checklist)

References

• The review of prescribing, supply and administration of medicines: A report on the Supply and Administration of Medicines under a group Protocol] Department of Health (1998).
• Review of supply and administration of medicines under group protocol. Preliminary report: Crown 2 (1). April. 1998, as implemented by HSC 1998/051., Department of Health (1999) Review of supply and administration of medicines. Final Report;
• Crown 2 (ii) March 1999. The supply and administration of medicines under group protocol arrangements, Royal College of Nursing 1998

Source: Northumbria NHS Health Care Trust diabetes protocol

• Brad Cheek: last updated Dec 2006
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