Diabetes mellitus Flashcards
1
Q
Metformin
Common indications
A
- Type 2 diabetes mellitus- first-line medication for control of blood glucose, used alone or in combination with other oral hypoglycaemic drugs (e.g. sulphonylureas) or insulin
2
Q
Metformin
MOA
A
- Metformin (biguanide) lowers blood glucose by increasing the response (sensitivity) to insulin.
- It suppresses hepatic glucose production (glycogenolysis and gluconeogenesis), increases glucose uptake and utilisation by skeletal muscle and suppresses intestinal glucose absorption
- It achieves this by diverse intracellular mechanisms, which are incompletely understood
- It does not stimulate pancreatic insulin secretion and therefore does not cause hypoglycaemia
- It reduces weight gain and can induce weight loss, which can prevent worsening of insulin resistance and slow deterioration of diabetes melitus
3
Q
Metformin
Adverse effects
A
- GI upset- N&V, taste disturbance, anorexia and diarrhoea
- This adverse effect may contribute to weight loss in patients taking metformin
- Lactic acidosis is a rare adverse effect associated with metformin use, which can be fatal if untreated
- It does not occur in stable patients, but can be precipitated by intercurrent illness that causes metformin accumulation (e.g. worsening renal impairment), increased lactate production (sepsis, hypoxia and cardiac failure) or reduced lactate metabolism (liver failure)
4
Q
Metformin
Warnings
A
- Severe renal impairment- contraindicated
- Moderate renal impairment- dose reduction required
- Withhold where there is AKI- sepsis, shock, dehydration
- Severe tissue hypoxia- cardiac or respiratory failure or MI
- Caution in hepatic failure- reduced clearance of lactate
- Acute alcohol intoxication- when it may precipitate lactic acidosis
- Chronic alcohol overuse
5
Q
Metformin
Interactions
A
- Metformin must be withheld before and 48 hours after injection of IV contrast media (CT scan, coronary angiogram)
- Drugs which impair renal function- ACEI, NSAIDs, diuretics)
- Prednisolone, loop diuretic, thiazide- they increase Blood glucose
6
Q
Metformin
Communication
A
- Take tablet with a whole glass of water with or after food
- Tablets are not a replacement for lifestyle measures (diet and exercise)
- Urgent medical attention- If they get vomiting, stomach ache, muscle cramps, SOB, severe tiredness- symptoms of lactic acidosis
- Tell doctors before surgery or X-ray may need to be stopped
7
Q
Metformin
Monitoring
A
- Assess blood glucose control by measuring glycated Haemoglobin (HbA1C)- the target should be <58mmol/mol)
- BG monitoring is not routinely required
- For safety, measure renal function before starting treatment, then at least annually
- Renal function should be measured more frequently (at least twice per year) in people with deteriorating renal function or at increased risk of renal impairment
8
Q
Insulins (General)
Common indications
A
- Insulin replacement for T1DM and control of BG in people with T2DM where oral agents are inadequate
- Given IV, in the treatment of diabetic emergencies such as diabetic ketoacidosis and hyperglycaemic hyperosmolar syndrome and perioperative glycaemic control is selected, diabetic patients
- Alongside glucose to treat hyperkalaemia while other measures are initiated
9
Q
Insulins (General)
MOA
A
- Functions the same as endogenous insulin
- It stimulates glucose uptake from the circulation into tissues, including skeletal muscle and fat, and increases the use of glucose as an energy source
- Insulin stimulates glycogen, lipid and protein synthesis and inhibits gluconeogenesis and ketogenesis
- For the treatment of hyperkalaemia, insulin drives K+ into cells, reducing Serum K- once insulin is stopped the K goes back into the blood (Short term while other agents are initiated)
- Rapid-acting insulin- insulin aspart- Novorapid
- Short acting- actrapid
- Immediate-acting- isophane insulin (NPH) e.g. Humulin I
- Long-acting- insulin glargine (Lantus)
- Biphasic- novomix (aspart/protamine)
10
Q
Insulins (General)
Adverse effects
A
- Hypoglycaemia- severe enough for coma and death
11
Q
Insulins (General)
Warnings
A
- renal impairment- insulin clearance is reduced, so there is an increased risk of hypoglycaemia
12
Q
Insulins (General)
communication
A
- When starting a patient with diabetes mellitus on insulin, explain that insulin will help to control blood sugar levels and prevent complications
- This is not a replacement for lifestyle changes
- Risk of hypoglycaemia, advising them of symptoms to watch out for (dizziness, agitation, nausea, sweating and confusion)
- Explain that if hypoglycaemia develops, they should take something sugary then something starchy
13
Q
Insulins (General)
Monitoring
A
- HbA1C
14
Q
Sulphonylureas (Gliclazide)
Common indications
A
- T2DM- as a single agent to control blood glucose and reduce complications where metformin is contraindicated or not tolerated
- In combination with metformin where blood glucose is not adequately controlled on a single agent
15
Q
Sulphonylureas (Gliclazide)
MOA
A
- Sulphonylureas lower BG by stimulating pancreatic insulin secretion
- They block ATP-dependent K channels in pancreatic B-cell membranes, causing depolarisation of the cell membrane and opening of voltage-gated Ca channels
- This increases intracellular Ca concentrations, stimulating insulin secretion.
- SU is only effective in patients with residual pancreatic function
- As insulin is an anabolic hormone, stimulation of insulin secretion by SU is associated with weight gain
- Weight gain increases insulin resistance and can worsen diabetes mellitus in the long term
28
Q
DPP4-i (Sitagliptin)
MOA
A
- Inhibits Dipeptidylpeptidase enzyme which increases insulin secretion and decreases glucagon secretion
39
Q
A
