Insulin for pharmacists

lmsg.nhs.uk

Insulin for pharmacists

Insulin

Elizabeth Hackett

Principal Pharmacist for Diabetes

18 th August 2009


Aims and Objectives

• To improve pharmacists’ ability to spot

errors when checking insulin prescriptions

– The key to this is in understanding the different

types of insulin and the different insulin

regimens used

• This presentation is therefore all about

insulin and different insulin regimens


Background

• Discovered 1921

• Available for clinical use 1923

• Revolutionised the treatment of diabetes

• Until 1980s insulin was extracted and purified

from the pancreas’ of pigs and cows

• Now human-sequence insulins are made mostly by

using recombinant DNA technology


Who needs insulin injections

• All with type 1 diabetes

• Many with type 2 diabetes, especially in

later life

– Poor control

– Infection / illness (MI)

– Surgery


Classification of insulins

• Time course of action

– Rapid, short, intermediate, long-acting

• Concentration

– U-100, (U-500)

• Species of origin

– Human, beef, pork


Rapid-acting

• Analogues

Insulin lispro (Humalog ® )

Insulin aspart (NovoRapid ® )

Insulin glulisine (Apidra ® )

• Onset of action: 5-15 mins

• Time to peak action: 30-90 mins

• Duration of action: 3-5 hours


Short-acting

• Aka soluble (or neutral) insulin

• E.g. Actrapid ® , Humulin S ® , Insuman Rapid ®

• Onset of action: 30-60 mins

• Time to peak action: 2-3 hours

• Duration of action: 5-8 hours


Intermediate-acting

• Isophane (or NPH) neutral protamine Hagedorn

• E.g. Insulatard ® , Humulin I ® , Insuman Basal ®

– Onset of action: 2-4 hours

– Time to peak action: 4-10 hours

– Duration of action: 10-16 hours


Long-acting

Insulin glargine (Lantus ® ) Analogue

– Onset of action: 2-4 hours

– Time to peak action: no peak

– Duration of action: 20-24 hours

Insulin detemir (Levemir ® ) Analogue

– Onset of action: 2-4 hours

– Time to peak action: 6-14 hours

– Duration of action: 16-20 hours


Insulin mixes

• Non analogue mixes

– Mixtard 30, Mixtard 50

– Humulin M3

• Analogue mixes

– NovoMix 30

– Humalog Mix 25, Humalog Mix 50


Normal Insulin Profiles

Basic Requirements

What happens

when you eat

Just to function normally

the body needs a constant level of sugar in the blood

After a meal

the blood sugar rises

and a background level of insulin

and extra insulin is needed


Normal daily insulin profile

Daily Requirements

Breakfast Lunch Evening Meal

Blood sugar

Mealtime insulin

Background insulin


Insulin injection regimens

• Single-daily injection of long-acting insulin

– Mostly used with oral agents and /or elderly type 2s

• Twice-daily injection of soluble plus isophane

insulin mixture

– fixed formulation of combinations of insulin (e.g.

Mixtard 30 - contains 30% soluble and 70% isophane)

given morning and evening

• Multiple injection (basal bolus therapy)

– 4 (or 5) daily injections

• 3 x rapid/short-acting insulin before each meal

• 1 (or 2) x long-acting insulin (as background / basal insulin)


One injection of long-acting

insulin per day

6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5

Breakfast Lunch Evening Meal Sleep


Two injections of 30/70 mix

(biphasic insulin) per day

6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5

Breakfast Lunch Evening Meal Sleep


4 Injections per day

3 Short + 1 Intermediate Acting

(Basal Bolus)

6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5

Breakfast Lunch Evening Meal Sleep


Does the insulin regimen make

immediate sense If not, question it

• Does this make immediate sense

1. Glargine OM, with NovoRapid TDS (with meals)

2. Mixtard 30 TDS

3. Humalog BD

4. NovoMix 30 BD

5. Hypurin Porcine Neutral TDS with Insulard ON

6. Actrapid TDS (with meals), with Insulatard ON

7. Glargine ON with NovoMix 30 TDS (with meals)

8. Detemir ON with gliclazide BD

9. NovoRapid TDS with meals


Does the insulin regimen make

immediate sense ANSWERS

1. Glargine OM, with NovoRapid TDS (with meals)

Yes, glargine gives 24 hour cover so does not really matter when injected, but more common

to see night-time dose

2. Mixtard 30 TDS

No, mixes normally given BD

3. Humalog BD

No, prescriber probably intends humalog mix 25 or 50

4. NovoMix 30 BD

Yes, this is standard practice

5. Hypurin Porcine Neutral TDS with Insulard ON

No, why pork short-acting with human intermediate-acting

6. Actrapid TDS (with meals), with Insulatard ON

Yes, this is an older regimen using non-analogue insulins

7. Glargine ON with NovoMix 30 TDS (with meals)

No, prescriber probably intends NovoRapid, not NovoMix

8. Detemir ON with gliclazide BD

Yes, this is standard practice

9. NovoRapid TDS with meals

No, this is unusual but may be correct for the individual patient


What device

• Device should be prescribed

– Pen

– Cartridge

– Vial (will need syringes)


U500 insulin

Humulin R ®

• U500 insulin is unlicensed

– Not in BNF

• Leicestershire is one of the biggest national

users of U500 insulin

• UHL is one of the few Trusts in the UK that

uses it – hence many staff are unaware of it

and unfamiliar with it

– Prescribers, pharmacists, nursing staff


U500

• U500 is 5 times more concentrated than standard

insulin

• U500 insulin is used for patients who are

extremely insulin resistant, who would otherwise

require large volumes of standard subcutaneous

insulin (usually >200 units daily)

• It is a soluble insulin

• It is normally injected TDS before meals


U500

• Prescribed in ‘marks’ not units

• ‘1 mark’ is a mark on a 0.3ml or 0.5ml

insulin syringe

• DO NOT USE 1ml INSULIN SYRINGES

AS MARKINGS ARE DIFFERENT

• 1 mark is 0.01ml, hence 1 mark of U500

insulin is 5 units


U500

• Most common current prescriber error is to prescribe units

instead of marks

• U500 insulin is used for patients who are extremely insulin

resistant, who would otherwise require large volumes of

standard insulin

• So if a prescription for U500 reads 20 units TDS, ask

yourself why can’t they use standard insulin at this dose as

20 units would be a small volume (0.2ml of U100)

• If the prescription reads 20 marks TDS this, is equivalent

to 100 units TDS which is would be a large volume of

standard insulin, hence the prescription makes sense.


Continuous IV insulin infusion

(sliding scale)

• Soluble insulin, given IV has a half life of 3-5

minutes

• IV insulin should be prescribed with IV glucose

(unless pt in DKA or HONK) as pt needs a

constant glucose source for continuous insulin

infusion

– Current guidelines recommend 5% glucose, new

guidelines will recommend 10% glucose

• If pt eating and drinking it is very hard to maintain

blood glucose within range when on IV insulin

– Can it be stopped


Continuous IV insulin infusion

monitoring

• Patients need to be monitored regularly

whilst on IV insulin as things can change

rapidly (hypoglycaemia)

– hourly monitoring for unstable patients,

2-hourly monitoring for more stable patients

• Check monitoring is being done regularly

– frequent Datix reports of inappropriate

monitoring leading to hypos


Continuous IV insulin infusion

(sliding scale)

• Check insulin solution has not expired (it

has 24 hour expiry from the time it was

made)

• IV insulin should be given through a ‘curly

whirly’ giving set. These sets are ‘low

sorption’ and insulin is not adsorbed onto

the plastic tubing – hence no need to prime

the line


Stopping a continuous IV insulin

infusion

• S/C insulin is not absorbed immediately (time

varies depending on what specific insulin is being

used)

• Oral anti-diabetic medicines also take time to be

absorbed

• For this reason it is recommended that IV insulin

is continued for 30 mins after subcutaneous

insulin has been injected or oral medicines taken

• In practice this rarely happens


Insulin storage

Insulin storage

– Unopened vials/cartridges/pens should be stored in fridge

– Once opened and in use, store at room temperature

• Cold injection more painful

• Absorption profile of cold insulin differs from that of room

temp insulin

– Check individual product package for length of time can

be used safely after opened (4-6 weeks)


Any questions or comments

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