What Is Metformin?

March 4, 2023

Metformin is a prescription medication used to treat type 2 diabetes. The medicine is available as an oral solution and tablet. Some patients may be able to take it as an extended-release tablet. Individuals who take the immediate-release oral tablet are typically started on an initial dose of 850 to one thousand milligrams per day. Doctors generally increase the patient's dose by five hundred milligrams each week until the maintenance dose (long-term daily dose) is reached. For most patients, the recommended maintenance dose is two thousand milligrams, and it is safe to take a maximum of 2,550 milligrams per day. If the extended-release tablet is prescribed, the initial dose is between five hundred to one thousand milligrams each day, and the maximum daily dose is two thousand milligrams. This medication is not recommended for individuals with impaired liver function, and elderly patients may be prescribed less than the maximum recommended dose.

How It Works

Metformin belongs to a group of medicines known as biguanides. These medicines were originally derived from French lilacs, and they were first introduced in the United States in the 1950s. Proguanil and chlorproguanil are both biguanides, and they are used to treat malaria. Metformin controls the level of glucose in a patient's blood by decreasing the amount of glucose absorbed from food and beverages. It reduces the amount of glucose the liver manufactures and helps the body become more sensitive to insulin (a hormone that regulates blood glucose). However, metformin does not affect the amount of insulin the body produces. Patients who have been diagnosed with type 2 diabetes will usually be offered metformin as the first treatment option. It may need to be used in combination with other medicines to achieve optimal blood glucose control.

Metformin Uses And Benefits

Metformin is approved for the treatment of type 2 diabetes in pediatric and adult patients. Although it is not officially approved for the treatment of type 1 diabetes, doctors may sometimes prescribe it off-label for this purpose. Physicians might consider it when treating patients with obesity. Studies suggest it may reverse weight gain that occurs as a side effect of olanzapine and other atypical antipsychotics. The medication could be beneficial for certain patients with polycystic ovarian syndrome as well, and some healthcare providers may prescribe it for patients with prediabetes, metabolic syndrome, or fatty liver disease. Metformin is currently being studied for its potential benefits in cancer prevention.

Potential Side Effects

While metformin causes fewer potential side effects than other diabetes medicines, patients have frequently experienced stomach issues such as gas, abdominal cramps, and nausea during metformin treatment. Other common side effects include upset stomach, diarrhea, sleepiness, decreased appetite, and back pain. Some individuals have reported painful urination and a general feeling of discomfort while taking this medicine, and it is common to develop a cough or hoarseness during treatment. Although less common, patients could notice blurry vision, headaches, and dizziness with metformin use. Anxiety, depression, nightmares, chest tightness, and facial redness have occurred as well. This medication can cause a metallic taste in the mouth, and some patients have experienced slurred speech, shakiness, changes in their nails, heartburn, and constipation.

Metformin is also associated with a rare side effect known as lactic acidosis. This potentially life-threatening condition often produces a skin rash and chest pain. Patients with these symptoms should be taken to the emergency room. It is important to let the prescribing physician know about any side effects that develop, especially if they are severe or persistent. Patients should also let their doctor know if side effects begin after they have already been taking metformin for a few weeks. It may be possible to reduce the dose so side effects are more tolerable.

Precautions To Remember

Before metformin is prescribed, patients should inform their doctor about any history of kidney disease, liver disease, heart disease, or diabetic ketoacidosis. It is also important to mention any history of stroke. Patients will have their kidney function tested before starting metformin. Individuals who drink alcohol regularly should let their doctor know since alcohol consumption and binge drinking during metformin treatment could increase the risk of developing lactic acidosis and cause changes in blood glucose readings. Patients who develop infections, severe diarrhea, vomiting, or fever during treatment with metformin should ask their doctor if they need to discontinue metformin for a short time.

If an x-ray procedure with contrast dye is necessary, patients may be advised to stop taking metformin for a few days before the procedure. Patients having surgery or dental procedures may need to adjust their dosing schedule as well. Metformin should be stored at room temperature, and it needs to be kept away from heat, light, and moisture. The liquid form of the drug needs to be dispensed with the provided dosing syringe or cup, and the extended-release tablet must be swallowed whole. Patients are encouraged to follow a healthy diet while taking metformin, and they should let their doctor know about any changes in their food intake or hydration levels.

Potential Medication Interactions

Metformin interacts with many other medications, and patients on this drug should ensure their doctor is aware of all the medicines and supplements they take. If metformin is taken with cimetidine (a medicine used to treat stomach ulcers), this could increase the amount of metformin in the body by as much as forty percent and cause patients to experience more side effects from metformin. Taking steroids, oral contraceptives, thiazide diuretics, or steroids with metformin may reduce the effectiveness of metformin and cause increased glucose. When patients stop using these medicines, they will need to be closely monitored for low blood glucose. To reduce the risk of drug interactions with metformin, patients should tell their doctor and pharmacist if they use angiotensin-converting enzyme inhibitors, beta-blockers, calcium channel blockers, morphine, or niacin. Individuals who take these medicines may need to have their metformin dose adjusted.

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