Metformin is a prescription drug used in combination with a good diet and exercise program to control and treat high blood sugar. It is used in treating patients with type 2 diabetes and sometimes off-label as insulin resistance for polycystic ovarian syndrome (PCOS). 

Controlling blood sugar can help prevent loss of sexual function, blindness, kidney damage, and nerve problems and lessen your risk of stroke or heart problems.  

Metformin works by restoring the body’s normal response to insulin. It also increases the amount of sugar absorbed by your intestines and produced by your liver. 

Metformin is available as oral tablets and oral solutions, and oral tablets are of two types: extended-release tablets and immediate-release tablets. Both tablet forms are available as generic drugs. Metformin belongs to a class of drugs called biguanides. 

Dosage of Metformin for Type 2 Diabetes

The adult dosage for metformin is a starting dose of 500mg two times daily or 850 mg once daily. Your doctor may increase it by 500mg weekly, but the maximum dosage is 2550 mg, while the maximum dosage for children (10 to 17 years) is 2000mg per day in divided doses.

The extended-release tablets are not recommended for children below 18, and both drug forms are not recommended for children below 10 years. 

Side Effects of Metformin

The common side effects of metformin include:

• Nausea.
• Diarrhea.
• Heartburn.
• Gas. 
• Stomach pain.

Some more severe side effects include:  

• Lactic acidosis.
• Hyperglycemia.
• Low vitamin D levels.

Precautions

Before taking this drug:

• Tell your doctor if you are allergic to it or any other medication.
• Tell your doctor if you have a medical history of breathing problems, blood problems, liver disease, or kidney problems.
• Before having any surgery or x-ray using iodinated contrast, tell your doctor that you are using metformin. You may need to stop the drug for a short time before having any procedure. 
• You may experience dizziness, blurred vision, or drowsiness after taking this drug due to extremely high or low blood sugar. Do not use machinery, drive or do anything that requires alertness. 
• It would also be best if you do not take alcohol or limit your alcohol intake when using metformin to reduce your risk of side effects such as low blood sugar and lactic acidosis. 
• Be sure to drink enough fluids to prevent dehydration when using this medication.
• During pregnancy or breastfeeding, discuss the benefits and risks of this drug with your doctor before taking it.
• Lastly, this drug may cause changes in the menstrual cycle and increase your chances of getting pregnant. Use reliable birth control methods when using the drug.