polycystic ovary syndrome (PCOS) associated with insulin resistance
Absorbed over 6 hours
Bioavailability is 50 to 60% under fasting conditions.
Administration with food decreases and delays absorption
Peak action occurs 3 hours after oral administration.
VOD is 654 L for metformin 850 mg administered as a single dose
Negligibly bound to plasma proteins
suppression of hepatic gluconeogenesis
activates AMP-activated protein kinase (AMPK)
Duration of action is 8-12 hours
The rare side effect, lactic acidosis, is thought to be caused by decreased liver uptake of serum lactate, one of the substrates of gluconeogenesis
Half-life 6.2 hours
Metformin is not metabolized and is excreted unchanged in the urine
Approximately 90% of the drug is eliminated in 24 hours in those with healthy renal function
Renal clearance of metformin is approximately 3.5 times that of creatinine clearance
Indicates that tubular secretion is the primary mode of metformin elimination.
Its main side effects are dyspepsia, nausea and diarrhea
Dose titration and/or use of smaller divided doses may decrease side effects
Risk of lactic acidosis means metformin should be avoided in:
severely compromised renal function (creatinine clearance < 30 ml/min)
acute/decompensated heart failure
severe liver disease
for 48 hours after the use of iodinated contrast dyes