Anti-Diabetic Medications Flashcards
Why are sulphonylureas considered second-line anti-diabetic drugs?
They reduce microvascular outcomes, but not macro vascular and diabetes-related death
What are possible adverse effects of sulphonylureas?
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.
Which sulphonylurea has the shortest half-life?
Glipizide has the shortest half life (3 hours) and is therefore less likely to cause hypoglycaemia.
Name four sulphonylurea drugs
- Glibenclamide
- Gliclazide
- Glimepiride
- Glipizide
How effective are thiazolidinediones compared to metformin and sulphonylureas
Reduce blood glucose concentration and HbA1c by a similar magnitude to metformin and sulphoylureas (~1.5% decrease in HbA1c). There is a lack of evidence that they improve diabetes-related clinical complications.
Name two thiazolidinediones
- Pioglitazone
2. Rosiglitazone
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.
What are some potential side effects of thiazolidinediones?
They are associated with modest weight gain predominantly due to salt and water retention. Therefore they are contraindicated in moderate to severe cardiac failure. 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. Do not prescribe rosiglitazone for people with known ischaemic heart disease.
How does acarbose work?
Acarbose decreases intestinal absorption of carbohydrates by inhibiting the conversion of polysaccharides and disaccharides into monosaccharides by alpha glucosidase.
What is the dose of acarbose?
50 mg daily - 100 mg tds (max dose 600 mg day)
How common are GIT side effects in patients taking metformin?
Gastrointestinal adverse effects occur in about 1/3 patients. To reduce these metformin is best started slowly (e.g. 500 mg daily) per day and titrated up based on GI adverse effects.
Aside from GIT side effects, what are some other adverse effects of metformin therapy?
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.
What are potential side effects of exanetide?
Gastrointestinal side effects are common. May rarely cause hypoglycaemia. Necrotizing pancreatitis is very rare but potentially fatal.
What are the main advantages and disadvantages of exanetide?
The main advantage of exenatide over other agents is the associated weight loss. The main disadvantages are route of administration by subcutaneous injection and cost (GLP-1 analogues are not subsidised on the PBS).
What type of drug is sitagliptin, and how does it work?
DPP-IV inhibitors (eg. sitagliptin) stimulate insulin secretion and suppress glucagon release by increasing concentrations of GLP-I and related peptides by blocking their metabolism.
