Metformin: Hypoglycemia and Lactic Acidosis Risks

Metformin is widely used for diabetes treatment, but concerns exist regarding hypoglycemia (low blood sugar) and lactic acidosis (a dangerous acid buildup in the blood). Research shows that when used correctly, metformin is generally safe and effective.

Key Points

• Hypoglycemia Risk: Low, but monitor blood sugar levels.
• Lactic Acidosis Risk: Higher in people with kidney disease—seek medical help if symptoms appear.
• Lactic Acidosis Symptoms: Weakness, trouble breathing, nausea, and extreme tiredness.
• Safe Use: Doctors should assess kidney function and other risk factors before prescribing metformin.

Metformin and Hypoglycemia: Background

Metformin was initially met with skepticism because of concerns about lactic acidosis, especially after a similar drug, phenformin, was removed from the market in 1976 due to safety issues.

Metformin faced delays in U.S. approval due to concerns over its safety. However, studies later showed that when taken correctly, metformin does not directly cause lactic acidosis and remains a safe and effective option for diabetes management.

Who Is at Risk for Lactic Acidosis?

• People with kidney disease
• Those with uncontrolled diabetes
• People with heart or lung conditions
• Heavy alcohol drinkers

Metformin’s Benefits and Safety

Metformin has been used for over 40 years and is proven to be safe for most people with type 2 diabetes.

It does not increase the risk of lactic acidosis when used properly, and the FDA has found no confirmed cases of metformin-induced lactic acidosis in normal use.

Why Take Metformin?

• Improves lifespan: Lowers the risk of diabetes-related death.
• Helps with weight control: May aid in weight loss or prevent weight gain.
• More effective than some other treatments: Works better than insulin or dietary changes alone in some cases.

How to Use Metformin Safely

To avoid risks, patients should be monitored regularly:

• Kidney Function Tests: Helps ensure the body can clear metformin properly.
• Watch for Symptoms: Fatigue, nausea, weakness, and trouble breathing could signal lactic acidosis.
• Blood Sugar Monitoring: Prevents hypoglycemia, especially if combined with other diabetes medications.
• Electrolyte Testing: Can help detect early signs of acid buildup in the blood.

Serious Risks: Hypoglycemia & Lactic Acidosis

Hypoglycemia (low blood sugar) can occur if metformin is taken with insulin or other diabetes medications. Symptoms include sweating, dizziness, confusion, and shakiness.

Lactic Acidosis is rare but serious and happens more often in people with kidney disease, heart problems, or heavy alcohol use. If severe, it may require hospital treatment, including dialysis.

Preventing Complications:

• Take the correct dosage.
• Stay hydrated and avoid excessive alcohol.
• Get regular kidney function tests.

Who Should Be Cautious with Metformin?

Doctors will closely monitor patients with:

• Kidney disease: Since metformin is removed through the kidneys, poor kidney function increases the risk of lactic acidosis.
• Liver disease: The liver helps process metformin, so people with liver conditions may face higher risks.
• Older adults (65+): Aging can reduce kidney function, increasing the chance of side effects.

Metformin and Future Research

Scientists are studying new benefits of metformin beyond diabetes treatment. Current research is exploring:

• Anti-aging effects and its potential to extend lifespan.
• Cancer prevention by slowing down the growth of certain cancer cells.
• Heart health improvements in reducing stroke and heart disease risks.
• Brain health protection , including studies on Alzheimer’s and Parkinson’s disease.

Metformin is also being studied for PCOS (polycystic ovary syndrome) and gestational diabetes.

Frequently Asked Questions

Does Metformin Cause Lactic Acidosis?

Lactic acidosis is extremely rare when metformin is used correctly. The risk is mainly in people with kidney disease or serious illness.

Does Metformin Cause Low Blood Sugar?

Metformin does not usually cause hypoglycemia on its own. However, the risk increases when combined with insulin or other diabetes medications.

Can Low Blood Sugar Lead to Lactic Acidosis?

Yes, severe hypoglycemia can lead to an increase in lactic acid levels. Proper blood sugar monitoring is important to avoid this.