Glycaemic Control in Long-Established Diabetes Flashcards
Name some sulphonylurea drugs
- Glibenclamide
- Gliclazide
- Glimepiride
- Glipizide
What are some potential side effects of sulphonylurea drugs?
Common adverse effects: hypoglycaemia, weight gain (~3 kg average). The risk of hypoglycaemia appears greatest with gibenclamide. Infrequent: nausea, diarrhoea, metallic taste, headache, rash. Rare: blood disorders, allergic reaction, photosensitivity, hepatotoxicity.
How do sulphonylurea drugs work?
Sulfonylureas are insulin secretagogues. They increase pancreatic insulin secretion and may decrease insulin resistance. They act by binding to receptors on the β-cell surface in the pancreas.
Which sulphonylurea is most likely to cause hypoglycaemia as a side effect?
Glibenclamide
Which sulphonylurea is least likely to cause hypoglycaemia as a side effect?
Glipizide has the shortest half life (3 hours) and is therefore less likely to cause hypoglycaemia.
What are some safety issues with thiazolidinediones?
Thiazolidinediones commonly cause fluid retention and hence increase the risk of heart failure. Long term use is associated with osteoporotic fractures in distal limbs. Thiazolidediones are contraindicated in moderate to severe heart failure. They may increase the risk of myocardial infarction. Additionally pioglitazone may increase the risk of bladder cancer.
How do thiazolidinediones work?
Thiazolidinediones (pioglitazone, rosiglitazone) increase peripheral insulin sensitivity by stimulating a nuclear receptor (peroxisome proliferator-activated receptor (PPARs) gamma) in tissues including muscle, fat and liver.
Give some examples of thiazolidinediones
- Pioglitazone
2. Rosiglitazone
What monitoring is required for patients on thiazolidinediones?
Rare side effects include elevated liver enzymes, hepatocellular injury, heart failure, pulmonary oedema. Monitor liver function before starting therapy and every 2 months for the first year.
When are thiazolidinediones used clinically?
Thiazolidinediones are a third-line oral treatment of type 2 diabetes after metformin and sulphonylureas. While they play a role in some patients, ensure thiazolidinedione therapy does not delay progression to insulin treatment.
When should dose adjustments of thiazolidinediones occur?
Doses should not be increased until after 8 weeks of treatment as full effect of the drug may not be seen before this time. Approximately 30% of patients do not have a significant response.
How does acarbose work?
Acarbose decreases intestinal absorption of carbohydrates by inhibiting the conversion of polysaccharides and disaccharides into monosaccharides by alpha glucosidase. Acarbose should be administered with meals.
What is the starting dose of metformin?
500mg daily
What is the maximum dose of metformin?
2-3g daily
A reduced maximum dose is suggested based on creatinine clearance: 60–90 mL/min 2 g daily, and 30–60 mL/min 1 g daily.
What are some potential side effects of metformin?
Lactic acidosis is rare (and controversial). Metformin should be avoided in patients with severe renal, hepatic or cardiac impairment,. Metformin should be withheld during, major illness (ie surgery, trauma, sepsis, myocardial infarction etc). and with contrast radiology. It may cause malabsorption of vitamin B12.
