Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

M301 > W6 Insulin formations (ZHM) > Flashcards

W6 Insulin formations (ZHM) Flashcards

1
Q

Insulin as a therapeutic peptide:
What is T1DM vs T2DM in terms of insulin?

A
  • Type 1 diabetes:
  • Pancreas no longer makes insulin
  • Type 2 diabetes:
  • Insulin made is not working properly,
    or
  • Pancreas produces more and more
    insulin to help, but over time becomes worn out and start to produce less insulin
    (body doesnt respond)

Insulin in a single insulin secretory
granule from a human pancreatic β-cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Types of insulin?
What is Bolus/Basal Insulin?
Short or long-acting?
When to take it?

A

Bolus insulin:
* Rapid acting/fast acting
* Short-acting
* Take before meals/snacks

  • Basal (background) insulin
  • Intermediate-acting insulin
  • Long-acting insulin
  • Take once or twice a day

Both= Mixed insulin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Why is a basal-bolus insulin regime used?

A
  • A basal-bolus insulin regime is used to mimic the body’s normal insulin production as closely as possible
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Rapid-acting Insulin
Onset?
Peak?
Duration?
Soluble?

A
  • Onset: 5 – 15 min
  • Peak: 30 – 90 min
  • Duration: < 5 h
  • Soluble insulin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Short-acting insulin:
Onset?
Peak?
Duration?
Generic Names?

A
  • Onset: 30 – 60 min
  • Peak: 2 – 3 h
  • Duration: 5 – 8 h
  • Insulin aspart, insulin glulisine, and insulin lispro
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Intermediate-acting
Onset?
Peak?
Duration?
Generic Names?

A
  • Onset: 2 – 4 h
  • Peak: 4 – 10 h
  • Duration: 10 – 16 h
  • Isophane insulin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Long-acting
Onset?
Peak?
Duration?
Generic Names?

A
  • Onset: Several hours
  • Peak: n/a (gradual)
  • Duration: ~24 h
  • Insulin detemir, insulin glargine, insulin degludec
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How many types of insulin?

A

4
Rapid-acting
Short-acting
Intermediate-acting
Long-acting

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Insulin structures?

A

Monomer: Rapid diffusion
Dimer: Limited diffusion
Hexamer: Minimal diffusion (Absorbed by lymph vessels due to large sizes)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Insulin structure (short-acting)
Structural differences

A

Insulin aspart: Aspartate on B28
Insulin lispro: Lysine on B28, Proline on B29
Insulin glulisine: Lysine on B3, Glutamic acid on B29

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Insulin structure (long-acting)
Structural differences?

A

Insulin detemir: C14 fatty acid chain on B29, omit B30
Insulin degludec: C16 fatty acid chain on B29, omit B30
(Dec solubility associates with albumin, forms a depot)
Insulin glargine: Glycine on A21, two Arginines after B30
(Isoelectric point- no net charge at a neutral pH, dec solubility)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Insulin structure (monomer, dimer and hexamer)
How is insulin formulated? To avoid what?

A
  • Short-acting insulin analogues inhibit dimer/hexamer formation, shift the equilibrium toward the monomeric state through amino acid modifications.
  • However, the insulin monomer is unstable and rapidly aggregates to form amyloid fibrils.
    Insulin is therefore primarily formulated as hexamers to prevent insulin aggregation.

Monomor to Amyloid fibrils
=Protein misfolding and aggregation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Insulin hexamer structure:

A
  • Insulin hexamer assembles with the zinc ion at the centre, coordinated to the B10
    (histidine residue) from each monomer unit.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Insulin structure (crystalline vs amorphous)
What are the differences?
How do these structures form?
Absorption short or long?
Duration of action short/long?

A
  • Crystalline
  • Rhombohedral crystals of size 10 - 40 μm
  • Slowly absorbed, long duration of action
  • Amorphous
  • No uniform shape, smaller than 2 μm
  • Quicker absorbed, short duration of action
  • In the presence of acetate buffer, Zn–insulin hexamers (building blocks) form an extremely insoluble complex of proteinaceous hormone.
  • Depending on the environmental pH, this complex can be crystalline or amorphous.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q
  • Insulin preparations which are intermediate in duration of action are prepared by physical mixtures of..?
A

crystalline and amorphous products.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Insulin structure (protamine)

A
  • Protamine (fish protein, sperm of trout) is added to the stable form of Zn–insulin hexamers, making NPH insulin (Neutral Protamine Hagedorn), such as isophane insulin.
  • Protamine is sparingly soluble in tissue fluid. It slowly breaks down so that the protamine suspension of active insulin is gradually released and absorbed, providing prolonged action.
  • They form rod-shaped crystals longer than 1 μm but rarely exceeding 60 μm.
17
Q

Insulin structure (mixed)
3 types of biphasic insulins?

A

Biphasic insulins:
* Biphasic isophane insulin (soluble/regular/neutral insulin + isophane insulin)
* Biphasic insulin aspart (insulin aspart + insulin aspart protamine)
* Biphasic insulin lispro (insulin lispro + insulin lispro protamine)

  • Pre-mixed insulin preparations containing various combinations of short-acting insulin and an intermediate-acting insulin.
  • Percentage of short-acting insulin varies from 15% to 50%, administered immediately before a meal.
18
Q

What is insulin made from? (2)

A

Human and animal insulin

Porcine: Alanine on B30
Bovine: Alanine on A8, Valine on A10, Alanine on B30 AA V
Sheep: Alanine on A8, Glycine on A9, Valine on A10, Alanine on B30 A G V A

19
Q

Types of insulin:
Insulin analogues

A

Rapid-acting:
* Insulin aspart (Novorapid)
* Insulin glulisine (Apidra)
* Insulin lispro (Humalog)

Slow-acting:
* Insulin detemir (Levemir)
* Insulin degludec (Tresiba)
* Insulin glargine (Lantus, Toujeo)
Types of insulin (made from)

Premixed:
* Humalog Mix 25 (25% insulin lispro + 75% insulin lispro protamine)
* Humalog Mix 50 (50% insulin lispro + 50% insulin lispro protamine)
* NovoMix 30 (30% insulin aspart + 70% insulin aspart protamine)
* Humulin M3 (30% soluble insulin and 70% isophane insulin)

Insulins must be prescribed and dispensed by brand name.

20
Q

Insulin Injection Devices?

A

Syringe:
* 30-unit (0.3 ml)
* 50-unit (0.5 ml)
* 100-unit (1.0 ml)

Cartridge:
* Disposable pen (most are):
Contains prefilled insulin cartridge
* Reusable pen: (more common now-less waste)
Contains replaceable insulin cartridge
* Insulin pump: Cartridge with rapid-acting insulin, delivered through small catheter inserted into subcutaneous tissue

  • Humalog 100 units/mL: Each mL contains 100 units of insulin lispro
  • NovoRapid 100 units/mL: Each mL contains 100 units insulin aspart
21
Q

Insulin pen features:

A

Pen cap
Injection button + Injection dial/dose knob
Dose window/counter
Insulin resevoir ( 3mL cartridge, 100 units/mL)
Rubber seal
Needle
Inner and Outer needle cover
Always use a new needle every time you inject insulin

22
Q

Storage and shelf-life
What reduces glucose-lowering potency? (2)

A
  1. Chemical degradation:Deamidation
  2. Physical degradation: Aggregation into fibrils
23
Q

What are the storage conditions for insulin, before and after use?

A

Before- Store in fridge (2-8°C)
After use- Room temperature up to 4 weeks
(Injecting cold insulin straight from the fridge can be painful)

24
Q

Excipients in insulin injections?

A
  • Zinc chloride: Form Zn–insulin hexamers
  • Preservatives: Phenol, meta-cresol
  • Tonicity agents: Glycerol, NaCl
  • Buffer: Disodium phosphate dihydrate, HCl, NaOH
  • Water for injections
25
Q

Counselling tip of NPH insulin?

A
  • Most insulin is clear, but some insulins (NPH insulin) are cloudy.
  • For cloudy insulin, it should be gently rolled and inverted (turned upside down) 10 times each until the solution is thoroughly mixed and becomes milky white.
  • Do not vigorously shake the insulin as this causes bubbles which could lead to inaccurate doses.
26
Q

Where shoud insulin be injected? (4)
What is Lipodystrophy?

A

Upper outer arms
Upper outer thighs
Abdomen (Semi circle below navel)
Buttocks

  • Lipodystrophy (abnormal fat distribution) may occur if injections are given repeatedly into the same area
  • Causes subcutaneous indentations (pitting)
  • Reduce vascularity in the affected area → slower absorption
  • Move around injection sites
27
Q

How to inject insulin? -Route of Administration (1)

Subcutaneous 45°
Intra Venous 25°
Intramuscular 90°
Intra Dermal 10-15°

A

Intramuscular 90°

Suspensions are not supposed to be injected
intravenously
Particles will travel through the venous system to the
heart and from there to the lungs
May become entrapped, preventing blood from
flowing, resulting in a pulmonary embolism

M301 (57 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions