Insulin Therapy

Question 1

Briefly describe the Basal-Bolus insulin regime

Answer 1

Multiple daily injection basal-bolus insulin regimens- the person has injections of short-acting insulin or rapid-acting insulin analogue before meals, together with one or more separate daily injections of intermediate-acting insulin or long-acting insulin analogue to cover the basal requirement

Question 2

Briefly describe the mixed (bisphasic) insulin regime

Answer 2

One, two or three insulin injections per day of short-acting insulin or rapid-acting insulin analogue mixed with intermediate-acting insulin

Question 3

Briefly describe the continuous subcutaneous insulin infusion (insulin pump) therapy

Answer 3

Programmable pump and insulin storage reservoir that gives a regular or continuous amount of insulin (usually in the form of a rapid-acting insulin analogue or short-acting insulin) by a subcutaneous needle or cannula

Question 4

What is the first-line insulin regime for treating type 1 diabetes?

Answer 4

Basal-Bolus regime

Question 5

What are the broad categories of insulin therapy?

Answer 5

• Rapid- and short-acting insulins have a quick onset of action and a short duration of action
  
  • They are used to replicate the insulin normally produced by the body in response to glucose absorbed from a meal or sugary drink
• Intermediate- and long-acting insulins have a slow onset of action and a long duration of action
  
  • They mimic the effect of endogenous basal insulin (insulin that is secreted continuously throughout the day)

Question 6

Rapid-acting insulins:

1. Onset of action
2. Duration of action
3. Examples

Answer 6

1. 15 minutes
2. 2–5 hours
3. Humalog® (insulin lispro) and Novorapid® (insulin aspart)

Question 7

Short-acting insulins:

1. Onset of action
2. Duration of action
3. Examples

Answer 7

1. 0–60 minutes
2. 8 hours
3. Actrapid® and Humulin S®

Question 8

Intermediate-acting insulins:

1. Onset of action
2. Maximal effects
3. Duration of action
4. Examples

Answer 8

1. 1–2 hours
2. 3–12 hours
3. 11–24 hours
4. Humulin I®, Insuman Basal® and Insulatard®

Question 9

Long-acting insulins:

1. Duration of action
2. Steady state level achieved
3. Examples

Answer 9

1. Up to 24 hours
2. 2–4 days
3. Lantus® (insulin glargine), Levemir® (insulin detemir) and Tresiba® (insulin degludec)

Question 10

What accessories are needed for a patient on insulin therapy?

Answer 10

• Insulin injection device
• Needles for pen injectors
• Blood glucose meter, test strips and lancets for self-monitoring of blood glucose
• Ketone meter, test strips and lancets
• Glucose and/or glucagon kit
• Accessories for sharps disposal

Question 11

How is insulin administered?

Answer 11

Insulin preparations are usually given by subcutaneous injection because insulin is destroyed by gastric acid and is not absorbed across the gut mucosa. For some people, insulin is given by subcutaneous infusion via an insulin pump.

Question 12

Give advice on injection sites of insulin therapy

Answer 12

To choose a body area that has plenty of subcutaneous fat, ensuring that the site and hands are clean. The main injection sites are:

• Abdomen- fastest absorption rate compared with other sites
• Outer thigh
• Buttocks
• Arm (not usually recommended due to the difficulty in injecting at this site)

If necessary, the skin should be ‘pinched up’ to avoid injecting into the muscle.

The injection site should be:

• Checked regularly for lumps (lipohypertrophy) and other injection site problems
• Rotated to prevent lipohypertrophy

Question 13

Give advice on target blood glucose self-monitoring levels for adults with type 1 diabetes

Answer 13

Advise routine self-monitoring of blood glucose levels at least 4 times a day (including before meals and before bed).

Discuss optimal targets for glucose self-monitoring.
The optimal targets for glucose self-monitoring in adults with type 1 diabetes are:

• Fasting plasma glucose level of 5–7 mmol/L on waking;
• Plasma glucose level of 4–7 mmol/L before meals at other times of the day;
• For adults who choose to test after meals, plasma glucose level of 5–9 mmol/L at least 90 minutes after eating.

Question 14

According to NICE, is continuous glucose monitoring currently recommended in type 1 diabetics?

Answer 14

No

Question 15

At what blood glucose level is hypoglycaemia defined as?

Answer 15

Levels fall to less than 3.5 mmol/L

Question 16

Briefly describe the presentation of hypoglycaemia

Answer 16

• Mild hypoglycaemia presents with a wide variety of symptoms, including hunger, anxiety or irritability, palpitations, sweating or tingling lips.
• As the blood glucose levels fall lower, the person may experience weakness and lethargy, impaired vision, and confusion or irrational behaviour. Cognitive function deteriorates when blood glucose levels fall to less than 3.0 mmol/L.
• Severe hypoglycaemia may result in convulsions, loss of consciousness, and coma. People with severe hypoglycaemia are unable to self-manage a hypoglycaemic episode and require help from another person to achieve normoglycaemia.

Question 17

How should an episode of hypoglycaemia be managed?

Note: if the person can swallow

Answer 17

• Promptly consume 10–20 g of a fast-acting form of carbohydrate (preferably in liquid form as this is easier to take)
• Recheck blood glucose levels after 10–15 minutes
• If there is no response or an inadequate response, repeat oral intake as above and re-test blood glucose levels after another 15 minutes

Question 18

How should an episode of hypoglycaemia be managed?

Note: if the person is unconscious and unable to swallow

Answer 18

• Intramuscular (IM) glucagon should be administered immediately
• Emergency transfer to hospital should be arranged (by calling 999) if:
  
  • IM glucagon is not available;
  • The family members/carers are not trained to administer glucagon;
  • Alcohol is the cause of, or has contributed to, the development of hypoglycaemia.
• If the person does not respond to glucagon treatment within 10 minutes→ emergency transfer to hospital
• If the person responds to glucagon treatment within 10 minutes and is sufficiently awake and able to swallow safely→ they should eat some oral carbohydrate

Question 19

Give examples of drugs that enhance the hypoglycaemic effects of insulin (and hence reduce insulin requirement)

Answer 19

• Alcohol
• Anabolic steroids
• Angiotensin-converting enzyme (ACE) inhibitors
• Beta-blockers
• Fibrates

Question 20

Give examples of drugs that antagonize the hypoglycaemic effects of insulin (and hence increase insulin requirements)

Answer 20

• Corticosteroids
• Diuretics (loop and thiazides)
• Glucagon
• Growth hormone
• Levothyroxine
• Oral contraceptives
• Sympathomimetic drugs (such as adrenaline, salbutamol, and terbutaline)

Question 21

What impact does type 1 diabetes have on driving risk?

Answer 21

• Remind drivers with diabetes of the need to be particularly careful to avoid hypoglyacemia
• Advise people with diabetes that it is the responsibility of the driving licence holder or applicant to notify the Driver and Vehicle Licensing Agency (DVLA) of their medical condition

Question 22

When should insulin therapy be considered in type 2 diabetes?

Answer 22

Insulin therapy should be considered (unless there is strong justification not to) if:

• Blood glucose levels are inadequately controlled despite dual therapy with metformin plus another oral antidiabetic drug
• Oral antidiabetic drugs are contraindicated or not tolerated

Question 23

When would insulin therapy not be suitable for type 2 diabetics?

Answer 23

• Obesity- insulin treatment may lead to further weight gain, with little or no improvement in blood glucose control
• Physical and mental health- the potential benefits of insulin therapy may not outweigh the potential risks, especially the risk of hypoglycaemia
• Anxiety about needles
• Personal preference
• Concerns relating to license to drive group 2 vehicles