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Adjusting your diet and exercising more are usually the first steps to controlling type 2 diabetes. If you still cannot maintain your target blood sugar, your healthcare provider may prescribe medication. Metformin is typically the first-line treatment.
This article discusses metformin, its side effects, and alternative medications used if metformin isn’t an option.
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Metformin belongs to a class of medications known as biguanides. It works by controlling blood sugar levels by reducing how much sugar gets absorbed from the food you eat into your system. It also decreases how much sugar is produced by the liver.
The drug was made a first-line therapy because of its ability to lower glucose (sugar) levels in the body, encourage weight loss, and reduce the risk for certain diabetes complications, such as vascular disease, which affects blood vessels. The risk of developing too-low blood sugar, often associated with other types of medication for diabetes, is also less a factor when taking metformin.
A biguanide is any medication that hinders the liver’s ability to produce glucose and the body’s ability to pick up glucose from food. These medications are also known for their cholesterol-lowering properties.
While metformin is generally considered safe, some known and common side effects are associated with the medication, including:
Some health conditions and lifestyle factors may prevent a person from being able to take metformin. They include:
People taking certain medications should also avoid metformin or speak to their healthcare provider before starting metformin therapy. Some drugs that may interact with metformin include:
Metformin may also reduce vitamin B12 levels in the body, so healthcare providers should monitor your B12 stores and have you supplement if necessary when taking the drug. Vitamin B12 is essential for nerve cells and blood health.
Some severe side effects, such as a rash or chest pain, are rare but can occur while taking metformin. Lactic acidosis, a severe and life-threatening condition, may also be caused by metformin use. Drinking large amounts of alcohol or taking certain medications such as Diamox (acetazolamide), Keveyis (diclofenamide), Topamax (topiramate), or Zonegran (zonisamide) can increase the risk of lactic acidosis.
Metformin is often prescribed with other medications or as a combination medicine to help control diabetes further. Some medications that can be prescribed with metformin include:
Metformin may also be used alongside other therapies for diabetes, such as insulin therapy, to help better manage the disease when insulin alone is no longer working as it should.
Combination medications are usually two drugs in one dose. For example, if a person takes an oral pill for their health condition, it will contain two drugs in one pill. Many diabetes medications are considered combination pills, with Metformin being one of the two drugs in many of them.
Metformin is a first-line therapy because of its effectiveness and safety. Typically, people who take metformin alongside lifestyle changes such as eating healthier and exercising more can manage their diabetes effectively.
In some cases, metformin has been used to prevent the onset of diabetes in people at a higher risk of developing the condition. Research has found that using metformin, along with lifestyle interventions, as a preventative technique can cut the risk of diabetes in half.
While metformin is the most commonly used medication for diabetes, it isn’t the only option. Many other drugs are used to manage the condition. The type of drug used depends on the personal factors of each person with type 2 diabetes.
The drugs mentioned above (thiazolidinediones, SGLT2 inhibitors, and DPP-4 inhibitors) are also options for people who cannot take metformin. Medications that encourage better insulin production may also be used and include sulfonylureas and glinides.
Insulin isn’t always needed for people with type 2 diabetes and is often reserved for those with type 1. People with type 2 diabetes that have tried other medications but haven’t seen any change in their condition are often good candidates for insulin.
Type 1 and type 2 diabetes differ. Type 1 diabetes develops when the pancreas, the organ that creates the hormone insulin, doesn’t produce enough to help the body manage blood sugar levels. Type 2 diabetes is more likely to occur when the body does not use the insulin created by the pancreas as well as it should. There is still enough insulin in the body, it is just not being used properly, leading to high blood sugar.
Metformin is used as first-line therapy for type 2 diabetes because it works to keep blood sugar levels controlled, and it is also safe and well-tolerated. While there is a list of side effects associated with the drug’s use, the most common tend to be gastrointestinal and include diarrhea and other stomach irritations.
While metformin is safe, some people may not be able to take it because of other medications they’re on, health problems such as liver or kidney disease, or if they consume incredibly high levels of alcohol regularly. Heavy alcohol consumption and metformin use can lead to a rare but life-threatening condition known as lactic acidosis.
In some cases, metformin is also prescribed alongside other diabetes drugs for the best results possible. These are referred to as combination drugs and make the condition much more manageable. There are different types of diabetes medications on the market. Still, they are typically used for people who can’t take metformin or have not seen any effective changes after taking the drug.
Having type 2 diabetes isn't always easy. Still, metformin is a well-tolerated and effective drug on the market today that many people with the condition can use to help manage their disease effectively. Using metformin may come with side effects, but since the drug is so effective and reduces the risk of low blood sugar, it's the best option for those with type 2 diabetes.
If metformin isn’t helping your diabetes, you must speak to your healthcare provider. They will look into your dosage and other medication options to see which works best for you. There are also other options to combine different drugs with metformin for better results.
No. People with type 2 diabetes rarely need insulin. That is because, in type 2 diabetes, the body still produces enough insulin. It just doesn’t use it properly. Insulin is necessary for people with type 1 diabetes because in this type the pancreas doesn’t produce enough insulin to handle blood sugar levels.
There is no cure for diabetes, including with the use of metformin. That said, the drug can effectively manage blood sugar levels long term for people with type 2 diabetes.
Medline Plus. Metformin.
Baker C, Retzik-Stahr C, Singh V, Plomondon R, Anderson V, Rasouli N. Should metformin remain the first-line therapy for treatment of type 2 diabetes? Ther Adv Endocrinol Metab. 2021 Jan 13;12:2042018820980225. doi:10.1177/2042018820980225
UK National Health Service. Who can and cannot take Metformin.
UK National Health Service. Taking Metformin with other medicines and herbal supplements.
Kim J, Ahn CW, Fang S, Lee HS, Park JS. Association between metformin dose and vitamin B12 deficiency in patients with type 2 diabetes. Medicine (Baltimore). 2019 Nov;98(46):e17918. doi:10.1097/MD.0000000000017918
Beysel S, Unsal IO, Kizilgul M, Caliskan M, Ucan B, Cakal E. The effects of metformin in type 1 diabetes mellitus. BMC Endocr Disord. 2018 Jan 16;18(1):1. doi:10.1186/s12902-017-0228-9
Aroda VR, Ratner RE. Metformin and type 2 diabetes prevention. Diabetes Spectr. 2018 Nov;31(4):336-342. doi:10.2337/ds18-0020
Informed Health. Medication for type 2 diabetes.
Meneghini LF. Insulin therapy for type 2 diabetes. Endocrine. 2013 Jun;43(3):529-34. doi:10.1007/s12020-012-9817-6
University of California San Francisco. Type 2 diabetes FAQs.
Angelica Bottaro is a professional freelance writer with over 5 years of experience. She has been educated in both psychology and journalism, and her dual education has given her the research and writing skills needed to deliver sound and engaging content in the health space.
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