Metformin for diabetes(diabetes tablets)
Metformin mrkedly differ from sulfonyl ureas(SU's) causes little or no hypoglycaemia in non diabetic person,and even in diabetics, episodes of hypoglycaemia are rare.
Metformin does not stimulate pancreatic beta-cells.
Metformin reported to improve lipid profile as well in type2 diabetics.
Metformin mechanism of action
They do not cause insulin release, but presence of insulin is essential for their action.Metformin is not effective in pancreatomized animals and in type 1 diabetics. Though the details are not clear,recent studies have recognized activation of AMP-dependent protein kinase(AMPK) to playa crucial role in mediating the action of metformin, the key features of which are -
1. Supperasive hepatic gluconeogenesis and glucose output from liver.This is the major action responsible for lowering of blood glucose in diabetics.
2. Enhances insulin-mediated glucose uptake and disposal in skeletal muscle and fat.
Insulin resistance exhibited by type 2 diabetics is thus overcome. This transaltes into -
- glycogen storage in skeletal muscle
- reduced lipogenesis in adipose tissue and enhanced faty acid oxidation.
3. Interferes with mitochondrial respiratory chain and promotes peripheral glucose utilization through anaerobic glycolysis.
AMPK activation by metformin appears to be an indirect consequence of interference with cellular respiration and lowering of intracellular ATP and other energy sources.
Metformin pharmacokinetics
Clearance of metformin approximates GFR. It accumulates in renal failure and increases the risk of lactic acidosis.
Plasma half life = 1.5-3 hours
Duration of action of metformin = 6-8 hours
Daily dose of metformin = 0.5-2.5gm
Number of doses of metformin per day = 1-2
Metformin uses
Metformin is now established as a first drug for all tyoe 2 diabetes mellitus patient, except when not tolerate or contraindicated.
Advantages of metformin:
- Nonhypoglycaemic
- weight loss promoting
- Antihyperglycaemic efficacy equivalent to other oral drugs.
- can be combined with any other oral or injectable antidiabetic, if one drug is inadequete.
Metformin has been found to improvr ovulation and fertility.
Metformin side effects
Anorexia
Metallic taste
Tiredness
Metformin does not cause Hypoglycaemia except in overdose.
Lactic acidosis - small increase in blood lactate
Vitamin B12 deficiency with high dose of metformin.
Metformin risk and Precautions
Avoided in Hpotensive states,Heart failure,severe respiratory,hepatic and renal disease.
Metformin interaction - Cimetidine,Furosemide may compete with metformin excretion and enhance its toxicity.
Questions described above -
What does metformin do exactly?
What are the most common side effects of metformin?
Why is metformin bad for you?
What is the benefit of taking metformin at night?
