Insulin Flashcards
Insulin is a __________ hormone secreted by pancreatic beta-cells
Polypeptide
Insulin increases glucose uptake by _________ tissue and ________, and suppresses _________ glucose release
Adipose
Muscles
Hepatic
The role of insulin is to lower ________ concentrations in order to prevent _________ and its associated ___________, __________ and ________ complications
blood-glucose
hyperglycaemia
microvascular
macrovascular
metabolic
The natural profile of insulin secretion in the body consists of _______ insulin (a low and steady secretion of background insulin that controls the glucose continuously released from the liver) and meal-time _______ insulin (secreted in response to glucose absorbed from food and drink)
basal
bolus
What are the three types of insulin available in the UK?
- Human insulin (produced by recombinant DNA technology)
- Human insulin analogues (same production as human insulin but modified to extend duration of action or increase rate of absorption and onset of action)
- Animal insulin (bovine or porcine); no longer initiated in people with DM but may still be used by some people who cannot or do not wish to change to human insulins
Is human insulin derived from human donors?
No; produced by recombinant DNA technology
How do human insulin analogues compare to human insulin?
Same mode of production but analogues are modiefied to produce desired kinetic characteristics such as an extended duration of action or faster absorption and onset of action
Is insulin allergy common?
No, true insulin allergy is rare; Human insulin and insulin analogues are less immunogenic than animal insulins
Why isn’t insulin administered orally?
Inactivated by GI enzymes; S/C route is ideal in most circumstances
What are the ideal insulin injection sites? (4)
Insulin should be injected into a body area with plenty of subcutaneous fat—usually the:
- abdomen (fastest absorption rate)
- outer thighs (slow absorption)
- buttocks (slow absorption)
- Inner thighs (also fast)
How does rate of absorption of insulin via S/C injection compare between the abdomen/inner thigh and the outer thighs/buttocks?
Slower absorption at outer thighs/buttocks vs fastest absorption at abdomen or inner thighs
What is the main disadvantage of administering insulin to the limbs?
Absorption can vary considerably (as much as 20-40%), particularly in children
What factors influence insulin absorption from limb sites? (6)
- Local tissue reactions
- Changes in insulin sensitivity
- Injection site
- Blood flow (eg increased due to exercise may increase absorption)
- Depth of injection
- Amount of insulin injected
____________ can occur due to repeatedly injecting into the same small area, and can cause erratic absorption of insulin, and contribute to poor glycaemic control.
Lipohypertrophy; Patients should be advised not to use affected areas for further injection until the skin has recovered
Lipohypertrophy can be minimised by __________
using different injection sites in rotation
Injection sites should be checked for signs of, __________, _________, ________, and __________ before administration
infection
swelling
bruising
lipohypertrophy
What are the metabolic consequences of lipohypertrophy?
can cause erratic absorption of insulin, and contribute to poor glycaemic control
What are the categories of insulin based on their time-actions? (3)
- Short-acting (including soluble insulin and rapid-acting)
- Intermediate-acting
- Long-acting
**the duration of action of each varies considerably from one patient to another and needs to be assessed individually
What are the available preparations of short-acting insulin?
- Soluble insulin (human and bovine or porcine although animal insulins rarely used)
- Rapid-acting insulin analogues
- insulin aspart
- insulin glulisine
- insulin lispro
What are the three types of rapid-acting insulin?
- Insulin aspart
- Insuline glulisine
- Insulin lispro
Soluble insulin is usually given subcutaneously but some preparations can be given _________ and __________
intravenously
intramuscularly
For maintenance regimens, soluble insulin is usually to injected____-____ minutes before meals
15 to 30
Remember, soluble insulin is short-acting
When injected subcutaneously, soluble insulin has a ________ onset of action (__________), a peak action between __________, and a duration of action of up to __________.
rapid
30 to 60 minutes
1 and 4 hours
9 hours
When injected intravenously, soluble insulin has a ______ half-life of _________ and its onset of action is __________.
short
only a few minutes
instantaneous
Soluble insulin administered ___________ is the most appropriate form of insulin for use in diabetic emergencies e.g. diabetic ketoacidosis and peri-operatively
intravenously
______________ administered intravenously is the most appropriate form of insulin for use in diabetic emergencies e.g. diabetic ketoacidosis and peri-operatively
Soluble insulin
Insulin aspart, insulin glulisine, and insulin lispro have a faster onset of action (within _________) and shorter duration of action (approximately ___________) than soluble insulin, and are usually given by subcutaneous injection
15 minutes
2–5 hours
For maintenance regimens, these insulins should ideally be injected ________ before meals
immediately
Rapid-acting insulin, administered before meals, has an advantage over short-acting soluble insulin in terms of ____________, __________, and _____________, including ____________
improved glucose control
reduction of HbA1c
reduction in the incidence of severe hypoglycaemia
nocturnal hypoglycaemia
Why should the routine use of post-meal injections of rapid-acting insulin be avoided? (3)
when given during or after meals, they are associated with:
- poorer glucose control,
- an increased risk of high postprandial-glucose concentration, and
- subsequent hypoglycaemia
Which insulin is considered “intermediate-acting?”
Isophane insulin
Isophane insulin has an _________ duration of action, designed to mimic the effect of endogenous _______ insulin
intermediate
basal
When given by subcutaneous injection, intermediate-acting insulins have an onset of action of approximately _________, a maximal effect at _________, and a duration of action of ________.
1–2 hours
3–12 hours
11–24 hours
Isophane insulin is a suspension of insulin with _________; it may be given as one or more daily injections alongside separate meal-time __________ injections, or mixed with a ________ insulin in the same syringe
protamine
short-acting insulin
short-acting (soluble or rapid-acting)
Isophane insulin may be mixed with a short-acting insulin by the patient, or a pre-mixed biphasic insulin can be supplied eg … (3)
- biphasic isophane insulin
- biphasic insulin aspart
- biphasic insulin lispro
__________ are pre-mixed insulin preparations containing various combinations of short-acting insulin (soluble insulin or rapid-acting analogue insulin) and an intermediate-acting insulin
Biphasic insulins (biphasic isophane insulin, biphasic insulin aspart, biphasic insulin lispro)
Biphasic insulin preparations should be administered by _______ injection __________ before a meal
subcutaneous
immediately
Like intermediate-acting insulins, the _________ mimic endogenous basal insulin secretion, but their duration of action may last up to 36 hours.
Long-acting insulins (protamine zinc insulin, insulin zinc suspension, insulin detemir, insulin glargine, insulin degludec)
Long-acting insulins have a duration of action up to ____ hours and achieve a steady-state level after ________ to produce a constant level of insulin
36
2-4 days
What are the different types of long-acting insulin? (5)
- Protamine zinc insulin
- Insulin zinc suspension
- Insulin detemir
- Insulin glargine
- Insulin degludec
Insulin glaringe is given ______ daily
Once (long-acting)
Insulin degludec is given ______ daily
Once (long-acting)
Insulin detemir is given _______ or _____ daily according to individual requirements
Once or twice (long-acting)
Unlike insulin glargine and insulin degludec, which are given once daily
The older long-acting insulins (2) are now rarely prescribed.
- insulin zinc suspension
2. protamine zinc insulin
Soluble insulin is ______-acting
Short
*Timing depends on route of administration:
When injected subcutaneously, soluble insulin has a rapid onset of action (30 to 60 minutes), a peak action between 1 and 4 hours, and a duration of action of up to 9 hours.
When injected intravenously, soluble insulin has a short half-life of only a few minutes and its onset of action is instantaneous.
Insulin aspart is ______-acting
Rapid
onset of action (within 15 minutes) and shorter duration of action (approximately 2–5 hours) than soluble insulin, and are usually given by subcutaneous injection
Insulin glulisine is ______-acting
Rapid
onset of action (within 15 minutes) and shorter duration of action (approximately 2–5 hours) than soluble insulin, and are usually given by subcutaneous injection
Insulin lispro is ______-acting
Rapid
onset of action (within 15 minutes) and shorter duration of action (approximately 2–5 hours) than soluble insulin, and are usually given by subcutaneous injection
Soluble insulin includes which types? (3)
- Human
- Bovine (rarely used)
- Porcine (rarely used)
Isophane insulin is _____-acting
Intermediate
onset of action of approximately 1–2 hours, a maximal effect at 3–12 hours, and a duration of action of 11–24 hour
Insulin detemir is _____-acting
Long
mimic endogenous basal insulin secretion, but their duration of action may last up to 36 hours. They achieve a steady-state level after 2–4 days to produce a constant level of insulin.
Insulin glargine is ______-acting
Long
mimics endogenous basal insulin secretion, but duration of action may last up to 36 hours. They achieve a steady-state level after 2–4 days to produce a constant level of insulin.
Insulin degludec is _______-acting
Long
mimics endogenous basal insulin secretion, but duration of action may last up to 36 hours. They achieve a steady-state level after 2–4 days to produce a constant level of insulin.
Zinc suspension and protamine zinc insulin are _____-acting
Long
Now rarely prescribed
mimic endogenous basal insulin secretion, but their duration of action may last up to 36 hours. They achieve a steady-state level after 2–4 days to produce a constant level of insulin.
Due to risk of overdose and death, when prescribing insulin, the words ‘_____’ or ‘____________’ should not be abbreviated
Unit
International unit
Specific insulin administration devices should always be used to measure insulin i.e. insulin ______ and ______
syringes
pens
**Insulin should not be withdrawn from an insulin pen or pen refill and then administered using a syringe and needle
What are the side effects of insulin? (4)
- Edema
- Lipodystrophy (alteration of the body’s pattern of fat distribution; also seen with HAART for HIV)
- Cutaneous amyloidosis (or lipohypertrophy)
- Hypoglycemia (in overdose)
What is the difference between lipodystrophy and lipohypertrophy?
Lipodystrophy refers BOTH lipohypertrophy and lipoatrophy; overall, these processes change the body’s pattern of fat distribution and the way the patient looks overall (more central fat, skinnier legs and arms). This is an acquired condition related to treatment with insulin as well as HAART (HIV).
Lipohypertrophy denotes a benign tumor-like swelling of fatty tissue at the injection site secondary to the lipogenic effect of insulin; this results from repeated injection at the same site and may interfere with insulin absorption
What is the difference between cutaneous amyloidosis and lipohypertrophy?
Cutaneous amyloidosis is the deposition of amyloid protein under the skin at sites of repeated insulin injection
Lipohypertrophy is the accumulation of fat under the skin at sites of repeated insulin injection
Both are side effects of insulin administration and BOTH have the potential to interfere with insulin absorption; therefore patients should be advised to rotate injection sites (to avoid both)
The dose of insulin generally needs to be _________ in the second and third trimesters of pregnancy.
increased
Is inuslin safe to use in pregnancy?
Yes; though dose may need to be adjusted
Is insulin safe to use during breastfeeding?
Yes, although insulin requirements may change and doses should be assessed by an experienced diabetes physician
How do insulin requirements change in cases of hepatic impairment?
Insulin requirements may decrease
How do insulin requirements change in patients with renal impairment?
May decrease
The compensatory response to hypoglycaemia is impaired in renal impairment
Since blood-glucose concentration varies substantially throughout the day, ‘normoglycaemia’ cannot always be achieved throughout a 24-hour period without causing damaging ___________
hypoglycaemia
What monitoring is required for patients taking insulin?
Many patients now monitor their own blood-glucose concentrations; all carers and children need to be trained to do this.
For adults, it is therefore best to recommend that patients should maintain a blood-glucose concentration of between _______ mmol/litre for most of the time (______ mmol/litre before meals and less than ___ mmol/litre after meals).
4 and 9
4–7
9
It is best to recommend that children should maintain a blood-glucose concentration of between _________ mmol/litre for most of the time (____ mmol/litre before meals and less than ____ mmol/litre after meals)
4 and 10
4–8
10
While accepting that on occasions, for brief periods, the blood-glucose concentration will be above target values; strenuous efforts should be made to prevent it from falling below ___ mmol/litre.
4
With _________ insulin regimens, the carbohydrate intake needs to be regulated, and should be distributed throughout the day to match the insulin regimen
fixed-dose
Patients using multiple injection regimens should understand how to adjust their insulin dose according to their ___________.
carbohydrate intake
What additional safety advice should be given to all patients and carers regarding all insulins? (3)
- Hypoglycemia is a potential problem with insulin therapy; all patients must be carefully instructed on how to avoid it including appropriate adjustment of insulin type, dose, and frequency together with suitable timing and quantity of meals and snacks
- Insulin passports and patient information booklets should be offered to patients receiving insulin; insulin passports provide a record of the patients current insulin preparations and contains a section for emergency information
- Drivers need to be particularly careful to avoid hypoglycemia and should be warned of the problems
What are the symptoms of hypoglycemia? (15)
- Sweating
- Feeling tired
- Dizziness
- Hunger
- Tingling lips
- Shaking or trembling
- Palpitations
- Irritably, tearfulness, anxiety, or moodiness
- Pallor
- Weakness
- Confusion
- Blurred vision
- Slurred speech or clumsiness (like being drunk)
- Seizures or fits
- Collapsing or passing out
A low blood sugar level, or hypo, can also happen while you’re sleeping. This may cause you to ________ during the night or cause _______, ______ or _______ in the morning.
wake up
headaches
tiredness
damp sheets (from sweat)
https://www.nhs.uk/conditions/low-blood-sugar-hypoglycaemia/
What steps should patients follow if their blood sugar falls below 3.5 mmol/L or they have symptoms of hypoglycemia? (3)
- Have a sugary drink or snack (not diet soda)
- Test blood sugar after 10 min; if improved, move to step 3. If there’s little or no change, treat again with a sugary drink or snack and take another reading in 10-15 min
- Eat your main meal (containing slow-release carbs) if it’s the right time OR a snack containing slow-release carbs if it’s not meal-time (eg biscuits or cow’s milk)
https://www.nhs.uk/conditions/low-blood-sugar-hypoglycaemia/
How do you treat someone who’s unconscious or very sleepy (drowsy) due to hypoglycemia? (5)
Follow these steps:
- Put the person in the recovery position and do not put anything in their mouth – so they do not choke.
- Call 999 for an ambulance if an injection of glucagon is not available, you do not know how to use it, or the person had alcohol before their hypo.
- If an injection of glucagon is available and you know how to use it, give it to them immediately.
- If they wake up within 10 minutes of getting the injection and feel better, move on to step 5. If they do not improve within 10 minutes, call 999 for an ambulance.
- If they’re fully awake and able to eat and drink safely, give them a carbohydrate snack.
They may need to go to hospital if they’re being sick (vomiting), or their blood sugar level drops again.
They should tell their diabetes care team if they ever have a severe hypo that caused them to lose consciousness.
How do you treat someone who’s having a seizure or fit due to hypoglycemia? (3)
Follow these steps if someone has a seizure or fit caused by a low blood sugar level:
- Stay with them and stop them hurting themselves – lie them down on something soft and move them away from anything dangerous (like a road or hot radiator).
- Call 999 for an ambulance if the seizure or fit lasts more than 5 minutes.
- After the seizure or fit stops, give them a sugary snack.
They should tell their diabetes care team if they ever have a severe hypo that caused them to have a seizure or fit.
In people with diabetes, what are the main causes of low blood sugar levels? (5)
- Medicines eg insulin, sulfonylureas, glinides, some antivirals used to treat hep C
- Skipping or delaying meals
- Not eating enough carbs in their last meal
- Exercise, especially if it is intense or unplanned
- Drinking alcohol
What information should be given to patients regarding how to prevent low blood sugar? (6)
- Check your blood sugar level regularly and be aware of the symptoms of a low blood sugar level so you can treat it quickly.
- Always carry a sugary snack or drink with you, such as glucose tablets, a carton of fruit juice or some sweets. If you have a glucagon injection kit, always keep it with you.
- Do not skip meals.
- Be careful when drinking alcohol. Do not drink large amounts, check your blood sugar level regularly, and eat a carbohydrate snack afterwards.
- Be careful when exercising; eating a carbohydrate snack before exercise can help to reduce the risk of a hypo. If you take some types of diabetes medicine, your doctor may recommend you take a lower dose before or after doing intense exercise.
- Have a carbohydrate snack, such as toast, if your blood sugar level drops too low while you’re asleep (nocturnal hypoglycaemia)
Can you continue driving if you have DM treated with insulin?
Yes, however you need to take measures to reduce the chance of having hypos while driving AND
You need to tell the DVLA and your car insurance company about your condition
________ injectable insulins can be given by continuous subcutaneous infusion using a portable infusion pump
Short-acting;
This device delivers a continuous basal insulin infusion and patient-activated bolus doses at meal times.
This portable insulin infusion pump delivers a continuous ______ insulin infusion and _________ bolus doses at meal times.
Basal
patient-activated
The portable insulin infusion pump technique can be useful for patients who suffer ___________ or marked __________ despite optimised multiple-injection regimens.
recurrent hypoglycaemia
morning rise in blood-glucose concentration
Patients on subcutaneous insulin infusion must be _________, able to ____________, and have _______________ from an experienced healthcare team.
highly motivated
monitor their blood-glucose concentration
expert training, advice and supervision
The ____________ effects of insulin may lead to weight gain
Lipogenic
What drug interactions should be considered when prescribing insulin?
Co-prescription with other drugs that may cause hypoglycemic episodes eg DPP-4 inhibitors, TZDs, leptins, metformin, GLP agonists, sulfonylureas, SGLT-2 inhibitors, and fibrates
You do not need to stop either drug BUT blood glucose monitoring should be increased and dose adjustment should be considered
