Metformin & Dementia


Metformin is a prescription drug that is used primary to treat Type II diabetes. In the United States, in addition to the generic version, it is sold under various brand names such as Fortamet, Glucophage, Glumetza, and Riomet. There are both immediate- and extended-release versions available. It is often prescribed by doctors as a first step in a diabetic’s regime as it is one of the most affordable option for them compared to other prescription medications.



Metformin tablets are used to treat high blood sugar levels caused by Type 2 diabetes. It works by reducing the amount of sugar released by the liver and improving how the body responds to insulin. The drug is normally used in combination with diet and exercise as well as a part of combination therapy with other drugs.

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Metformin’s main ingredient is a compound known as guanidine. The compound was discovered in a 3-foot tall flowering plant known called ‘goat’s rue’. It was found that the guanidine compound in the plant helped lower blood sugar levels. However, guanidine by itself can be toxic. It only becomes a useful tool when two guanidine compounds are combined. The compound was refined in the late 1950s in France, but only gained FDA approval in 1994.

Since metformin is often prescribed with other diabetes drugs, some manufacturers have combined metformin with another drug within a single pill for more convenient therapy. These include:

  • Kazano
  • Invokamet & Invokamet XR
  • Xigduo XR
  • Synjardy & Synjardy XR
  • Metaglip
  • Glucovance
  • Jentadueto & Jentadueto XR
  • PrandiMet
  • Avandamet
  • Kombiglyze XR

Janumet & Janumet XR

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Metformin is considered to put very little strain on the organs and doesn’t cause weight gain as some other drugs may. However, there are still a number of side effects, some mild and some severe. Some of the common side effects include:

  • Diarrhea
  • Nausea
  • Stomach pain
  • Heartburn
  • Gas

Most of these effects tend to be mild and may go away within a few days or a couple of weeks. However, for some patients it may be more severe. In such cases, doctors may prescribe extended-release versions instead of immediate release tablet. If the problem persists, then doctors may switch to a different drug.

A couple of possible serious side effects include lactic acidosis and hypoglycemia (low blood sugar). In such instances, it is important to get immediate medical attention. Lactic acidosis is characterized by:

  • Tiredness
  • Weakness
  • Unusual muscle pain
  • Trouble breathing
  • Unusual sleepiness
  • Stomach pains, nausea, or vomiting
  • Dizziness or lightheadedness
  • Slow or irregular heart rate

Lactic acidosis, if ignored, is a potentially fatal condition. It occurs when dangerously high levels of lactic acid build up in the bloodstream. Those who have kidney disease, liver, disease, congestive heart failure, or those who consume alcohol regularly are at a greater risk of developing lactic acidosis. In such instances, other medications may be better suited to treat the Type II diabetes.

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While metformin is mainly known as a drug that is used to treat Type II diabetes, it is sometimes prescribed to treat other health issues as well. For example, it is sometimes used to treat polycystic ovarian syndrome (PCOS), a metabolic disorder that affects women of childbearing age. In addition to lowering insulin levels, metformin is can also lower the amount of testosterone produced by the body. And PCOS being a condition associated with excess testosterone, metformin may help restore regular menstrual cycles and improve metabolism.

In other instances, it may also help reduce the chance of miscarriage or gestational diabetes and improve the chance of successful in-vitro fertilization. However, according to the NIH, research on such treatments are inconclusive. It should also be noted that the drug is not approved for such uses by the FDA and therefore has to be taken with caution and in consultation with a doctor.

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Unlike treating PCOS or reducing the chance of gestational diabetes, the opinions and recommendations on metformin use in patients with dementia are inconclusive. On one hand, some studies indicate that metformin may reduce the risk of dementia, such as Alzheimer’s. and on the other hand, other studies have indicated that long-term use may, in fact, increase it.

Meta analyses of different studies that looked into the connection between metformin and dementia have mostly concluded that there are no clear correlations overall.A few other studies have indicated that the drug can still be used as a first line of therapy for diabetic patients at risk of developing dementia. However, the use of metformin by individuals without diabetes for the prevention of dementia is not recommended.

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Whether or not metformin should be prescribed for treating symptoms of dementia is a controversial topic. With some studies showing a positive impact and others showing a negative impact, the matter requires a well-informed discussion with the patient’s doctor.

Firstly, the progression of the patient’s dementia must be assessed. The drug might not increase risks if the person is in late stage dementia. But it may pose higher risk for someone still in the early stages of progression. In addition, whether or not the patient is diabetic should also be accounted for. If they are diabetic also, then often metformin can be the right medication for them. However, if they are not diabetic, then the pros and cons of taking the drug must be considered before making a decision that is suitable for the patient.

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