Biguanides, particularly metformin (Glucophage), are insulin sensitizers that enhance glucose uptake, thereby reducing insulin resistance. Unlike sulfonylureas, metformin doesn't prompt insulin secretion, which helps to curb hypoglycemia risk. Metformin is beneficial in treating conditions like polycystic ovary syndrome due to its insulin-resistance reduction capability. The drug's primary action involves curtailing hepatic gluconeogenesis, a significant contributor to high blood glucose levels in type 2 diabetes. Furthermore, it slows intestinal sugar absorption and boosts peripheral glucose usage, potentially leading to weight loss through appetite suppression.
Metformin is the recommended initial treatment for type 2 diabetes by the American Diabetes Association (ADA), either as a standalone medication or combined with other agents or insulin. However, combining it with insulin may lead to hypoglycemia, requiring dose adjustments. Metformin's adverse effects, predominantly gastrointestinal, like nausea, vomiting, and diarrhea, can be mitigated by gradual dosage increase and mealtime administration. It's contraindicated in cases of renal dysfunction, acute myocardial infarction, sepsis, and situations potentially leading to acute renal failure. Vitamin B12 deficiency is a potential long-term side effect.
Another class of insulin sensitizers, Thiazolidinediones (TZDs), including pioglitazone (Actos) and rosiglitazone (Avandia), don't stimulate insulin release from pancreatic β cells, averting hyperinsulinemia risk. TZDs function as peroxisome proliferator-activated receptor-γ (PPARγ) agonists, enhancing insulin sensitivity in various tissues. They can be used alone or combined with other glucose-lowering agents or insulin. The ADA recommends pioglitazone as a secondary or tertiary agent for type 2 diabetes treatment, while rosiglitazone usage is limited due to potential cardiovascular risks. Both drugs are well absorbed orally, bind to serum albumin, and undergo extensive metabolism. TZDs can cause weight gain and osteopenia and increase bladder cancer risk, particularly with pioglitazone. They should be avoided in patients with severe heart failure.
Biguanides are insulin sensitizers that enhance glucose uptake, reducing insulin resistance.
Unlike sulfonylureas, they do not stimulate insulin secretion, mitigating hypoglycemic risk.
They decrease hepatic gluconeogenesis, a prevalent source of high blood glucose in type 2 diabetes.
It also slows intestinal sugar absorption, boosts peripheral glucose uptake, and causes loss of appetite, potentially inducing weight loss.
Metformin is the drug of choice for type 2 diabetes. However, its usage requires careful dosage adjustments and is contraindicated in cases of renal dysfunction and acute myocardial infarction or heart failure.
Thiazolidinediones represent another class of insulin sensitizers. They are used alone or combined with other oral hypoglycemics or insulin.
Thiazolidinediones function as PPARγ receptor agonists, lowering insulin resistance.
Pioglitazone is recommended as a second or third-line agent for type 2 diabetes, while rosiglitazone's use is limited due to potential cardiovascular risks.
Their adverse effects include weight gain, edema, osteopenia, and increased fracture risk in women.
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