Diabetes Mellitus Flashcards
Stepwise pharmacological management of diabetes mellitus
- first line: metformin
- add SGLT-2 inhibitor once settled on metformin if existing CVD or heart failure
- second line: add sulfonylurea, pioglitazone, DPP-4 inhibitor or SGLT-2 inhibitor
- third line: triple therapy (*metformin + 2 second line drugs) | insulin therapy
Outline insulin release
- secreted by B cells in pancreas
- in response to increase [glucose] + incretins
- parasympathetic response M3
What is insulin release inhibited by?
- Decreased [glucose]
- Cortisol
- (Sympathetic response a2)
What is the role of insulin?
- Decrease hepatic glucose output via inhibition of gluconeogenesis + glycogenolysis > increasing glycogen stores
- Promote uptake of glucose into muscle + adipose tissue
What is the half life of insulin?
5 minutes in plasma
What are the diagnosis factors of type 1 diabetes mellitus?
- Polyuria
- Polydipsia
- Weight loss
- HbA1c >48mmol/mol
- hyperglycaemia
- plasma or urine ketones
What does HbA1c measure?
- Percentage of RBCs with ‘sugar coating’
- Reflects average blood sugar over last 10-12 weeks
- in mmol/mol
Why is insulin secreted in blood even during fasting
Prevents down regulation of receptors
Why is insulin routinely administer s.c and not p.o?
It is a protein - to avoid digestion in gut
What is human insulin made from?
Recombinant DNA
Enzymatic modification of porcine
What ways are insulin preparations made for slow absorption?
- protamine / zinc complex with natural insulin
- soluble insulin form hexamers
- insulin analogues
Reason for rotating site of insulin administration
To limit lipodystrophy
Affect of insulin analogies on pharmacokinetics + pharmacodynamics
- changes PK
- doesnt change PD
List the insulin types from fastest acting to slowest
- insulin aspart
- soluble insulin
- NPH
- insulin glargine
What are adverse effects of insulin?
Hypoglycaemia
Lipodystrophy
How should insulin be prescribed?
By brand name
Contraindications of insulin
Renal impairment
Hypoglycaemia risk
What are the important drug drug interactions of insulin
- Dose needs to be increased with systemic steroids
- other hypoglycaemic agents
Outline the speed of action of basal bolus dosing
- bolus: rapid acting e.g. aspart
- basal: long acting e.g. glargine
- tries to mimic ‘normal’ insulin profile in non diabetic person
What are the different types of insulin?
Examples
- rapid acting insulins - novorapid
- short acting insulins - actrapid
- intermediate acting insulins - hummulin I
- long acting insulins - levemir + lantus
- combination insulins - humalog 25, humalog 50, novomix 30
How long does it take for rapid acting insulins to work + how long do they last?
Example
- start working after 10 mins
- last 4 hours
- novorapid
How long does it take for short acting insulins to work + how long do they last?
Example
- start working after 30 mins
- last for 8 hours
- actrapid
How long does it take for intermediate acting insulins to work + how long do they last?
Example
- start working after 1 hour
- last for 16 hours
- humulin I
How long does it take for long acting insulins to work + how long do they last?
Example
- start working in 1 hour
- last for 24+ hours
- levemir, lantus
What are combination insulins?
Examples
Contains rapid acting + intermediate acting insulins
humalog 25
humalog 50
novomix 30
What is diabulimia?
When a type 1 diabetic stops or reduces their insulin to control their weight
Differentiate between [glucose] and HbA1c?
- [glucose]: immediate measure of glucose levels at that moment in time
- HbA1c: % of RBCs with sugar coating - average blood sugar over last 10-12 weeks
Do you need to increase or decrease insulin in a patient with renal impairment?
decrease
Due to reduced renal clearance of insulin > hypoglycaemic risk
What is the first line drug treatment of diabetes mellitus?
Metformin