Metformin HCL (Glucophage)

What is Metformin?

Metformin is a prescription medication used to treat and prevent type 2 diabetes. If left untreated, type 2 diabetes can result in serious complications that can affect your heart, kidneys, eyes, and nervous system.

What does Metformin do exactly?

In type 2 diabetes, sugar (glucose) levels in the blood become too high. Metformin decreases glucose levels in the blood. 

How does Metformin work?

Type 2 diabetes occurs when your pancreas stops producing enough insulin, or your body becomes less sensitive to the effects of insulin.  Insulin is needed by the body to control your blood sugar levels.

Metformin helps to reduce the levels of glucose in your blood in three ways:

• By lowering the amount of glucose produced in the liver
• By increasing the body’s response to insulin. 
• By blocking the absorption of glucose by the intestine

How long does it take for Metformin to work?

Metformin usually takes about two days to affect blood sugar levels. You will typically start with a low dose of 500mg daily and build up to 2000mg daily over a few weeks if needed. While increasing the dose slowly helps avoid side effects, it also means that you won’t notice a rapid change in your blood sugar.  

What is Metformin used for, other than diabetes?

Metformin only has FDA approval for use in type 2 diabetes. However, it has been found to be effective for a number of other conditions, including prediabetes, gestational diabetes (diabetes during pregnancy), and polycystic ovarian syndrome (PCOS). A Metformin prescription for any condition other than diabetes is considered “off-label”.  Although off label use is perfectly legal, it is up to the prescribing physician to weigh the risks and benefits of the medication for other purposes.  

How does Metformin help PCOS?

Polycystic ovarian syndrome (PCOS) is characterized by the overproduction of male hormones, enlarged ovaries, and irregular ovulation. Many women with PCOS will also have high levels of insulin, which increases their risk of developing diabetes. As Metformin helps to regulate insulin, it has been used as an off-label treatment for PCOS. However, it is only likely to be prescribed for PCOS if you already have diabetes or prediabetes. This is because other treatments may be more appropriate and better tolerated.

Active ingredients

Metformin contains the active ingredient metformin hydrochloride. Different brands of Metformin, such as Glumetza, Glucophage, Glucophage XR, and Fortamet all contain the same active ingredient. 

Inactive ingredients

The inactive ingredients in Metformin are candelilla wax, cellulose acetate, hypromellose, magnesium stearate, polyethylene glycols (PEG 400, PEG 8000), polysorbate 80, povidone, sodium lauryl sulfate, synthetic black iron oxides, titanium dioxide, and triacetin.

Please note: inactive ingredients may vary between different manufacturers. 
 

Which ingredients can cause an allergic reaction?

Symptoms of a severe allergic reaction include, facial or lip swelling, feeling dizzy, finding it hard to breathe and rash/hives. While a severe allergic reaction to this medication is rare, you should keep a lookout for these symptoms if you are using the medication for the first time. If you do notice any of these symptoms shortly after taking the medication please seek medical help right away. 

How do you use Metformin?

You should always take Metformin as prescribed by your doctor. When you first start Metformin, you will be prescribed 500mg daily or twice daily. Over a few weeks, this dose will be gradually increased up to a maximum of 2000mg (2g) daily. 

Metformin is available in standard or extended-release tablets. Standard-release tablets are normally taken twice daily, whereas extended-release tablets are taken daily. 

It is advisable to take Metformin with a meal where possible, to reduce the chances of experiencing nausea and other gastrointestinal side effects. 
 

What doses of Metformin are available?

Metformin (Glucophage) is available in 500mg, 750mg, 850mg and 1000mg doses. 
Metformin Extended-Release (Glucophage XR) is available in 500mg and 750mg doses. 

What is the best time of day to take Metformin?

If you are taking standard-release Metformin, you will normally take the medication twice daily and sometimes three times a day.  If you are prescribed the extended-release Metformin, you will usually take the medication once daily at night.  

Whichever type of Metformin you are taking, it is usually recommended that you take Metformin with a meal. This helps to reduce the side effects you may experience. 

What is the benefit of taking Metformin at night?

Your doctor should let you know when to take Metformin. Taking extended-release Metformin at night helps reduce the occurrence of high blood glucose levels early in the morning.

What should I do if I miss a dose of Metformin?

If you forget to take Metformin, skip the dose you forgot and take your next dose at the usual time. You should not take two tablets to compensate. Consider setting an alarm or marking your pillbox with the appropriate administration times to avoid missing doses.

What happens if you take too much Metformin?

Taking too much Metformin can cause serious complications. If you feel you may have taken too much Metformin, you should seek immediate medical attention. Take the pill packet or bottle and the patient information leaflet with you. 

Can Metformin be crushed?

Metformin should not be split, crushed, or chewed. Breaking up a tablet causes it to dissolve and absorb too quickly, which can lead to dangerous side effects. This is especially important for extended-release tablets, as they contain a much higher dose of Metformin, designed to dissolve and be absorbed over several hours. 

What are the most common side effects of Metformin?

The most common side effects of Metformin are:

• Abdominal pain
• Reduced appetite
• Diarrhea (usually this only lasts for a short time)
• Gastrointestinal disorders
• Nausea and vomiting
• Altered sense of taste

Starting Metformin at a low dose and taking Metformin with meals should help to reduce the side effects that you experience.
 

How long do Metformin side effects last?

Most side effects will resolve after two weeks of taking Metformin. If you experience diarrhea when taking Metformin, this should resolve within a few days. Most people will start on a low-dose of Metformin to help reduce the likelihood and degree of side effects. If you experience persistent side effects, or if your side effects significantly impact your life, you should discuss this with your doctor, who may be able to adjust your dose or offer alternative medications. 

What are the bad side effects of Metformin?

There are few severe side effects of Metformin. In rare cases, Metformin can cause hepatitis (inflammation of the liver), skin reactions and a condition called lactic acidosis. The symptoms of lactic acidosis are:

• Abdominal pain or discomfort
• Decreased appetite
• Fast or shallow breathing
• Diarrhea
• Severe muscle pain or cramping
• Unusual weakness or fatigue
• A general feeling of being unwell

With Metformin, as with all medications, a severe allergic reaction (anaphylaxis) may occur. Symptoms of a severe allergic reaction include:

• Rash
• Itching
• Swelling - especially of the face, tongue or throat
• Breathing difficulties
• Dizziness

If you experience any of these symptoms listed above, you should seek emergency medical attention. 
 

What are the side effects of long term use of Metformin?

Metformin is designed to be taken long-term to regulate blood sugar levels.  Therefore some side effects may occur after long-term use.  Up to 30% of people taking Metformin long-term will experience vitamin B12 deficiency. This can produce symptoms of fatigue, headaches, heart palpitations, loss of balance, loss of appetite, and resultant weight loss, among other symptoms. Vitamin B12 deficiency is easily treated; however, permanent consequences can occur if the deficiency persists for an extended period.

What are the side effects if you stop taking Metformin?

You should only stop Metformin if instructed to do so by your doctor, or if you experience significant side effects. Stopping Metformin can increase your blood sugar levels and diabetic symptoms. If you would like to stop taking Metformin, you should discuss this with your doctor. 

What should you not eat when taking Metformin?

There are no specific foods that you must avoid when taking Metformin. However, Metformin can interact with alcohol, increasing your risk of lactic acidosis. In addition, alcohol can impair your body’s ability to manage glucose, so it is recommended that you avoid drinking alcohol when taking Metformin. 

While there are no foods that you must avoid when taking Metformin, you may want to make some dietary changes to help regulate your blood sugar. Refined carbohydrates, such as white bread, rice, and pasta, along with sugary foods, can have a big impact on your blood sugar levels. To avoid increasing your blood sugar levels, you can avoid these foods or replace refined carbohydrates with complex carbohydrates such as wholewheat bread and brown rice.
 

Are there any precautions when taking Metformin?

Metformin should not be prescribed for individuals who are at risk of developing lactic acidosis. Risk factors for lactic acidosis include: 

• Chronic heart failure 
• Medications that can affect kidney function
• Dehydration (you should rehydrate then continue taking Metformin)
• Impaired kidney function
• Conditions that can cause tissue hypoxia (low oxygen levels)

Symptoms of lactic acidosis include stomach discomfort, reduced appetite, diarrhea, rapid or shallow breathing, general discomfort, severe muscle pain and cramping, and weakness and fatigue.

Metformin may also interact with certain medications, including the contrast dye used in some x-rays and CT scans. 

Make sure you tell the prescribing doctor about any conditions or medications that you take so that they can make sure Metformin is safe for you.
 

What drugs should not be taken with Metformin?

Metformin can interact with several medications, so it is important to let the prescribing doctor know if you are taking any prescription drugs, recreational drugs or herbal medicines. For a full list of Metformin drug interactions, please see the patient information leaflet included with your prescription. 

When should Metformin be stopped?

Metformin may be stopped if it is no longer suitable for you or if you no longer need treatment. You should only stop taking Metformin if you have a severe reaction, or if you are told to do so by your doctor. 

Metformin is only effective as long as the pancreas produces insulin. If Metformin is no longer treating your diabetes, your doctor may need to prescribe a different medication, such as insulin. 

Some people can experience severe side effects from Metformin, which can significantly interfere with their quality of life. If this applies to you, speak to your doctor about alternative treatment options. 

Diabetes is not always a life-long condition. Gestational diabetes usually resolves shortly after giving birth.  Type-2 diabetes may also go into remission with weight loss.  A hemoglobin A1C of less than 6% for over three months may be a cause to stop taking Metformin.  Along with medications, a healthy diet, weight management and regular exercise are imperative to managing diabetes.
 

What can I take instead of Metformin?

Metformin is the first choice of treatment for type 2 diabetes. However, there are other options available.

• Sulfonylureas
• Meglitinides
• Thiazolidinediones
• Dipeptidyl-peptidase 4 (DDP-4) inhibitors
• Alpha-glucosidase inhibitor
• Sodium-glucose cotransporter-2 (SGLT2) inhibitors

If these medications do not work for you, you may need to take insulin. Insulin is taken via injection and it acts to replace the insulin that is no longer being produced by your pancreas. 
 

Which is better, insulin or Metformin?

Metformin is the first-line treatment for type 2 diabetes as recommended by the American Diabetes Association. However, Metformin will only work as long as your pancreas is producing insulin. If your pancreas stops producing insulin, you will require insulin replacement therapy. People with this stage of diabetes are often known as insulin-dependent diabetics. 

Are Metformin and Metformin HCL the same?

Metformin contains the active ingredient metformin hydrochloride. Therefore, it is sometimes referred to as Metformin HCL. Metformin is also known under brand names including, Glumetza, Glucophage, Glucophage XR, Riomet and Fortamet.  All of these contain the same active ingredient. 

Metformin standard-release vs extended-release

Metformin is available in different forms. The standard-release version is quickly dissolved by the stomach and absorbed into the body. Therefore, you will usually have to take this two or three times a day for a sustained effect. An extended-release version, referred to as Metformin SR or XR, is also available. Extended-release tablets are dissolved slowly over a longer period of time. This means that it will be absorbed by the body at a slower rate and you can expect more sustained effects over time. An advantage of extended-release tablets is that you can take a larger dose in one tablet, so you don’t have to take your tablets so frequently. 

• Rx List > Metformin
• Drugs.com > Metformin
• Diabetes Forecast > Wait Times
• Therapeutic Advances in Endocrinology and Metabolism > Role of metformin in the management of polycystic ovary syndrome
• Mayo Clinic > Metformin
• The Journal of Clinical Endocrinology and Metabolism > Long-term Metformin Use and Vitamin B12 Deficiency in the Diabetes Prevention Program Outcomes Study
• Diabetes Care > How do we define cure of diabetes?
• CDC > Gestational diabetes
• Experimental and clinical endocrinology and diabetes > Effectiveness of Metformin on Weight Loss in Non-Diabetic Individuals With Obesity
• Mayo Clinic > Prediabetes
• CDC > Prediabetes
• Research Gate > Does anyone in the RG community know the mechanism of diarrhea caused by metformin?
• PDR > Metformin Hydrochloride