RECALL OF METFORMIN EXTENDED RELEASEIn May 2020, the
Food and Drug Administration (FDA) recommended that some makers of metformin extended release remove some of their tablets from the United States market. This is because an unacceptable level of a probable carcinogen (cancer-causing agent) was found in some extended-release metformin tablets. If you currently take this drug, call your doctor. They will advise whether you should continue to take your medication or if you need a new prescription.
Typically, doctors advise that people minimize alcohol while they take metformin. Both alcohol and metformin put stress on the liver, intensifying the effects of both.
Metformin is a medication that helps individuals manage type 2 diabetes and occasionally other conditions, such as polycystic ovary syndrome (PCOS).
Drinking small amounts of alcohol while taking this drug may not cause harm, but frequent or excessive alcohol consumption may cause life threatening side effects.
In this article, we look at the possible interactions between metformin and alcohol as well as the complications that might occur after mixing them.
Alcohol and metformin can interact with each other. For this reason, people who take metformin need to be careful about how much alcohol they consume.
The National Health Service (NHS) in the United Kingdom says those taking metformin may be able to have up to 2 units of alcohol daily or no more than 14 units weekly.
Two units of alcohol are equivalent to 1 bottle of beer or 1 small glass of wine.
However, for some people, this may also be unsafe. For example, those with liver conditions may risk worsening the condition if they continue drinking.
It is important for anyone taking metformin to consult a doctor about using alcohol while taking the medication.
Metformin works by improving insulin sensitivity, promoting the uptake of glucose (blood sugar) into tissues and reducing sugar levels in the bloodstream.
By increasing the effectiveness of the glucose already circulating in the body, metformin reduces the amount of glucose that both the liver produces and the intestines absorb.
However, when a person drinks alcohol, it has significant effects on blood sugar.
One of the liver’s main functions is removing toxins such as alcohol from the body. As a result, it undergoes stress when a person drinks alcohol.
When the liver has to process a lot of alcohol, it overworks, becoming tired, which results in releasing less glucose. This can result in hypoglycemia, or low blood sugar.
Long-term alcohol use can also make cells less sensitive to insulin. This means that they absorb less glucose from the blood, and levels in the bloodstream increase.
Over time, alcohol consumption damages the liver, especially when a person drinks to excess. It reduces the liver’s ability to produce and regulate glucose.
Conditions, such as alcohol-induced hepatitis and cirrhosis of the liver, can occur with chronic alcohol use, greatly decreasing liver health and impairing blood glucose control.
Although an occasional drink may not be harmful, the potential effects may outweigh the benefits. People need to speak with their doctor about whether it is safe for them.
Gastrointestinal complications are the most common side effects of metformin. Many side effects of this drug are the same as those of alcohol, so mixing the two can intensify symptoms.
The extent of alcohol’s influence on the side effects of metformin depends on the amount of alcohol a person drinks as well as their individual health.
Usually, the more alcohol someone consumes and the faster they ingest it, the greater the risk of interactions.
Common metformin side effects that alcohol use worsens include the following:
- abdominal pain or discomfort
- muscle cramping
- vomiting
- nausea
- loss of appetite
- excess gas
- sour stomach
- indigestion or heartburn
Taking metformin with food and drinking enough fluids may prevent many of its side effects. Once the body adjusts to the medication, many side effects tend to resolve.
In some cases, people with diabetes who consume alcohol while taking metformin can experience life threatening complications.
Hypoglycemia
Metformin helps regulate blood sugar levels. It does not usually cause low blood sugar on its own, but this can occur in combination with other factors.
This can occur if a person:
- takes too large a dose of metformin or insulin
- does not eat regularly or fasts
- does not get adequate nutrition from their diet
- exercises too much
- has another condition, such as thyroid, kidney, or liver disease
- takes other medications or supplements
- consumes excess alcohol
Alcohol also causes dips in blood sugar levels, so in combination with metformin, it can cause hypoglycemia.
The symptoms of mild hypoglycemia, such as headaches, tiredness, and hunger, can be vague or difficult to identify. People may also mistake them for signs of alcohol consumption, meaning they do not realize they are experiencing low blood sugar.
Drinking alcohol before bedtime can also lead to blood sugar dips during the night, which may interfere with sleep.
Some more serious signs of hypoglycemia include:
- sweating
- shaking or trembling
- anxiety
- confusion
- difficulty concentrating
In severe cases, these symptoms can get worse or become life threatening. If this occurs, people need to call 911 immediately.
Severe symptoms include:
- racing heartbeat
- exhaustion
- vision changes
- nausea
- difficulty staying awake
- passing out
Drinking alcohol with meals or carbohydrates may help prevent hypoglycemia in people taking metformin. If symptoms occur, consuming fast-absorbing carbohydrates, such as glucose gel or sugar cubes, can treat them.
If symptoms present, people with blood sugar monitors can check their levels. If eating carbohydrates does not return blood sugar levels to typical levels after 10 to 15 minutes or the symptoms become more intense, individuals can consume more doses until they stabilize.
If symptoms are intense, people need to call emergency services right away.
Lactic acidosis
Lactic acidosis is a rare but dangerous side effect of metformin, occurring in an estimated
This condition is a consequence of the muscles mainly producing their energy by using oxygen-dependent processes.
During strenuous or prolonged activity, the body can need more oxygen than is available, so the cells switch to anaerobic, or oxygen-lacking, processes.
Anaerobic glucose breakdown produces lactic acid, which breaks down further into lactate. The liver then processes this into glucose.
Lactate levels can rise during extended exercise or strenuous activities, as the body needs oxygen to help clear it. When lactate does not clear from the bloodstream quickly enough, it can build up, increasing blood and muscle acidity.
When lactate levels are too high, lactic acidosis occurs. Metformin and alcohol both slow the rate of lactate uptake by the liver.
Signs of lactic acidosis can be subtle and nonspecific at first, though severe lactic acidosis has intense symptoms that are quick to appear. If any symptoms occur, people need to seek immediate medical attention.
Potential signs of lactic acidosis include:
- muscle cramping or pain, particularly around the gut
- intense weakness
- fatigue
- diarrhea
- headache
- general discomfort
- loss of appetite
- fast or shallow breathing
- fluttering or fast heartbeat
- low blood pressure
- nausea
- vomiting
- seizures
Vitamin B12 deficiencies
Metformin
The initial symptoms of a deficiency can be subtle, and a severe B12 deficiency has serious risks, such as nerve damage.
If a person suspects they may have a B12 deficiency, they need to seek medical advice. Potential signs include:
- anemia symptoms, such as dizziness, pale skin, fatigue, and shortness of breath
- tingling in the hands and feet
- difficulty thinking, concentrating, or remembering
- mood changes, such as irritability or depression
- twitching or uncontrollable movements
- difficulty walking
- a smooth, red tongue
- changes in smell or taste
- diarrhea
- unexplained weight loss
Supplements or dietary changes can reverse most B12 deficiencies and reduce any symptoms. Vitamin B12 is present in high levels in foods such as beef, eggs, dairy products, and shellfish.
People with diabetes using metformin need to discuss B12 screening options with their doctor.
It is occasionally safe to drink a moderate amount of alcohol while taking metformin. However, regularly drinking excessive amounts can cause drug interactions, which can range from mild to severe.
Drinking excess alcohol while taking metformin may cause hypoglycemia, vitamin B12 deficiency, or, in rare cases, lactic acidosis. This is a potentially lethal condition.
As a result, it is important for people taking metformin to be cautious about drinking alcohol. A doctor can advise if it is safe for a person to drink while taking the drug and how individuals can minimize the risks.