Buformin

Buformin is an oral biguanide antidiabetic agent, structurally related to metformin and phenformin, used in the management of type 2 diabetes. Like other biguanides, buformin works by reducing the amount of glucose produced by the liver, decreasing the absorption of glucose in the intestines, and increasing the body's sensitivity to insulin. However, due to concerns over its association with lactic acidosis, a rare but serious condition, its use has been limited in many countries and it has been withdrawn from others.

Mechanism of Action

Buformin lowers blood glucose levels primarily by inhibiting gluconeogenesis, the process by which the liver produces glucose from non-carbohydrate sources. It also increases the sensitivity of muscle cells to insulin, facilitating the uptake of glucose, and decreases the absorption of glucose in the intestines. Unlike sulfonylureas, buformin does not increase insulin secretion from the pancreas, which means it does not cause hypoglycemia when used alone.

Pharmacokinetics

The absorption of buformin after oral administration is incomplete and variable. It is excreted unchanged in the urine. The half-life of buformin is relatively long, allowing for once or twice daily dosing in most patients.

Adverse Effects

The most common adverse effects of buformin are gastrointestinal in nature, including nausea, vomiting, diarrhea, and abdominal discomfort. These side effects are dose-related and can often be reduced by taking buformin with meals. More serious, but less common, is the risk of lactic acidosis, particularly in patients with renal impairment or other conditions predisposing to the condition. For this reason, buformin is contraindicated in patients with renal, liver disease, and in those with a history of alcohol abuse.

Clinical Use

Buformin was used in the treatment of type 2 diabetes, particularly in patients who were overweight, as it does not cause weight gain, a common side effect of many other antidiabetic agents. However, due to the risk of lactic acidosis, its use has been restricted in many countries, and it is no longer available in others.

Comparison with Other Biguanides

While buformin, metformin, and phenformin all belong to the biguanide class of antidiabetic drugs, there are important differences in their pharmacokinetic profiles and safety. Metformin is the most widely prescribed biguanide, largely because it has a more favorable safety profile, particularly with respect to lactic acidosis. Phenformin has been withdrawn from the market in many countries due to its higher risk of lactic acidosis compared to metformin.

Conclusion

Buformin is a biguanide antidiabetic agent with a mechanism of action similar to that of metformin. Its use has been limited by concerns over lactic acidosis, and it has been withdrawn from the market in several countries. Metformin remains the biguanide of choice for the treatment of type 2 diabetes due to its efficacy and safety profile.