Metformin is likely one of the most prescribed medicines on the planet, with greater than 150 million individuals presently taking it for kind 2 diabetes administration (and, in some instances, weight reduction).
Whereas it’s usually nicely tolerated, like all medicines, it might have unintended effects.
On this article, we’ll have a look at how metformin works; its widespread, unusual, and critical unintended effects; and methods to alleviate these unintended effects.
Key Factors:
- Widespread unintended effects embrace gastrointestinal points comparable to diarrhea, flatulence, and nausea. Some individuals might also expertise a metallic style after taking the medication.
- Lengthy-term use can result in vitamin B12 deficiency and, in uncommon instances, lactic acidosis. It’s necessary to observe for these situations carefully.
- Negative effects could be managed by adjusting the remedy’s dosage, switching to extended-release types, or combining it with sure different medicines. Some individuals, comparable to these with sure kidney or liver points, ought to keep away from metformin.
How metformin works
Metformin (model names Glucophage, Glucophage XR, Fortamet, Glumetza, and Riomet, plus numerous generics) works by decreasing the quantity of sugar the liver releases all through the day and growing the physique’s sensitivity to insulin.
It additionally reduces the quantity of glucose (sugar) that’s absorbed from the meals you eat, which in flip reduces your blood sugar ranges after consuming.
Widespread unintended effects of metformin
The most typical unintended effects of metformin embrace:
- Diarrhea (various from gentle to extreme)
- Flatulence (passing gasoline)
- Nausea or vomiting
- Bloating and constipation
- Abdomen discomfort
- Heartburn
- Headache
- Decreased urge for food and weight reduction
- Muscle ache or cramping
- A metallic style within the mouth
One other widespread facet impact of metformin is weight reduction. Though the medication isn’t FDA-approved for this use, it’s often prescribed off-label for this objective. Within the Diabetes Prevention Program (DPP) Research, common weight reduction amongst metformin customers was roughly 4.4 to six.6 kilos over two to 3 years.
Unusual (critical) unintended effects of metformin
Vitamin B12 deficiency
Latest analysis has proven that long-term use of metformin can lead to vitamin B12 deficiency in some individuals. Signs of vitamin B12 deficiency can embrace:
- Anemia
- Irritation of the tongue
- Fatigue
- Palpitations
- Pale pores and skin
- Dementia
- Weight reduction
- Infertility
Left untreated, B12 deficiency could cause important nerve injury, finally resulting in a analysis of peripheral neuropathy.
If a health care provider isn’t conscious of this threat, they may misdiagnose the reason for an individual’s neuropathy as being the results of excessive blood sugar ranges when it might in reality be a facet impact of the B12 deficiency attributable to metformin.
This nerve injury is irreversible, however additional injury could be prevented by supplementing with an everyday dose of vitamin B12.
Everybody taking metformin ought to have their B12 ranges examined yearly. In session with their healthcare supplier, anybody with insufficient ranges ought to begin taking a B12 complement instantly. (Vitamin B12 injections each few months could also be really helpful in some instances.)
Lactic acidosis
There have been a big variety of research on metformin’s threat of inflicting lactic acidosis — a doubtlessly deadly situation by which lactic acid builds up within the physique. Signs of lactic acidosis can embrace:
- Nausea
- Vomiting
- Weak point
- Fatigue
- Quick, deep respiration
- Muscle cramps and physique aches
Metformin comes with a “black field” warning about this threat, essentially the most extreme warning that the U.S. Meals and Drug Administration (FDA) points.
That stated, in response to “The Phantom of Lactic Acidosis attributable to Metformin in Sufferers With Diabetes,” printed within the American Diabetes Affiliation’s (ADA) journal Diabetes Care, the overwhelming majority of research discovered no situations of lactic acidosis in individuals taking metformin.
“The variety of documented instances of metformin-associated lactic acidosis is small when one considers how broadly metformin is used,” explains the ADA. “That metformin has been used safely in sufferers with contraindications could be seen as proof that it doesn’t trigger lactic acidosis.”
Nearly all instances of lactic acidosis from metformin use are outcomes of overdoses — not regular use of the drug.
“Instances of lactic acidosis from metformin overdoses, significantly in younger individuals with out threat elements, counsel that metformin could cause lactic acidosis primarily if given in massive doses.”
These most prone to growing lactic acidosis whereas on metformin embrace individuals with situations comparable to kidney or liver points, a historical past of coronary heart assaults or acute coronary heart failure, and frequent alcohol customers.
Hypoglycemia (low blood sugar)
Metformin solely very not often causes hypoglycemia in individuals with diabetes who’re not taking insulin injections, as a result of it doesn’t improve insulin manufacturing like many different diabetes medicines.
Name your physician you probably have any signs of hypoglycemia, which might embrace:
- Weak point
- Tiredness
- Nausea
- Vomiting
- Abdomen ache
- Dizziness
- Lightheadedness
- Abnormally quick or gradual heartbeat
“Faux” low blood sugar
Whereas this isn’t a detrimental facet impact, it’s an necessary state of affairs to pay attention to when beginning on metformin.
Whenever you drop your blood sugars to a “regular” vary after operating persistently excessive for some time, you might expertise “faux” signs of low blood sugar.
As a result of your physique has change into used to excessive blood sugars, returning to regular ranges might make you are feeling dizzy, lightheaded, nauseous, and intensely hungry.
This could move after a couple of days to weeks as your physique adjusts to your new regular blood sugar ranges.
If you happen to’re feeling low, at all times verify your blood sugar to be sure you aren’t experiencing an actual low blood sugar (sometimes thought of to be beneath 70 mg/dl) that requires remedy with glucose.
Allergic reactions to metformin
Allergic reactions to metformin are uncommon, however they do occur. Signs of an allergic response can embrace:
- Rash
- Hives
- Itching
- Swelling of the face, lips, or tongue
- Problem respiration
If you happen to expertise any of those signs, search medical consideration instantly.
How lengthy after taking metformin do unintended effects begin?
Metformin’s unintended effects normally seem rapidly after the primary dose, and whereas they enhance for some individuals after a couple of weeks, others might discover they persist.
Others might not even start to expertise unintended effects till they’ve been taking the drug for months or a yr.
Lowering metformin unintended effects
Happily, there are some things you are able to do to alleviate, reduce, or altogether stop the unintended effects attributable to metformin.
Take your dose throughout your meal, not earlier than
One key step is to take your metformin dose midway via consuming your meal, slightly than earlier than you begin consuming.
Folks taking the medication report far much less abdomen misery if there’s already meals of their abdomen by the point their metformin dose is being digested.
Begin with a really small dose
By beginning with an especially small dose, as a substitute of the complete dose your physician would usually prescribe on your top and weight, you might be able to drastically cut back these initially uncomfortable unintended effects.
If that is an strategy you’d prefer to attempt, discuss to your physician about adjusting your doses as a way to give your physique time to acclimate to the drug.
Learn extra: Metformin Dosage Information (Min and Max Doses)
Ask for the “extended-release” model
Too usually, docs prescribe the common (standard- or immediate-release) model as a right for the extended-release (ER or XR) model.
When utilizing the ER/XR model of metformin, the remedy is regularly launched over a number of hours as a substitute of instantly. This course of successfully lessens undesirable gastrointestinal signs.
Though it might be dearer, this strategy can considerably lower the general unintended effects of metformin.
Nonetheless, you might have to attempt the common model first. That is so your physician can inform your insurance coverage firm that you just tried it and it wasn’t the fitting remedy for you. Then they are going to be extra prone to cowl the extended-release model.
Take your dose entire
It is necessary to not crush, break, or chew your metformin tablets, as doing so might trigger them to be absorbed extra rapidly and improve the chance of unintended effects.
Mix it with different diabetes medicines
In case your healthcare supplier intends to begin you on a GLP-1 drug, the unintended effects of metformin can really assist counterbalance the constipating unintended effects of lots of the medicines on this class.
GLP-1 medicines for diabetes presently accessible in america embrace the next:
- Dulaglutide (model identify Trulicity)
- Exenatide (Byetta)
- Exenatide prolonged launch (Bydureon bcise)
- Liraglutide (Victoza, Saxenda)
- Lixisenatide (Adlyxin)
- Semaglutide (Ozempic, Rybelsus)
By together with each kinds of medication in your diabetes administration plan, the unintended effects might assist basically stability one another out.
Learn extra: Metformin Mixture Medication for Type 2 Diabetes
Attempt one thing else
There are some individuals who merely don’t tolerate metformin. If you happen to discover you can not bear the unintended effects, discuss to your healthcare crew.
If you happen to select to cease taking metformin, they can assist you discover a totally different kind of diabetes remedy to handle your blood sugar ranges.
Learn extra: The Greatest Alternate options to Metformin for Type 2 Diabetes Administration
Meals to keep away from to attenuate unintended effects
Specialists don’t particularly suggest avoiding any explicit meals whereas taking metformin to forestall gastrointestinal unintended effects comparable to diarrhea.
That stated, there are specific meals and drinks that may improve the chance of those points normally, so you might need to cut back your consumption of them in case you are experiencing gastrointestinal discomfort with metformin. These embrace:
- Sugar
- Synthetic sweeteners
- Dairy merchandise
- Garlic, onions, and different meals excessive in FODMAPs (sure sugars which are poorly absorbed and should trigger intestinal misery)
- Fructose (a pure sugar present in fruit)
- Gluten (a protein present in wheat, rye, barley, and their hybrids)
- Fried or fatty meals
- Spicy meals
- Alcohol
- Caffeine
These modifications may assist handle gastrointestinal signs comparable to diarrhea whereas taking metformin.
Who ought to keep away from taking metformin?
As with all medicines, there are specific individuals who shouldn’t take metformin.
The first concern with metformin facilities on its potential to extend the chance of extreme lactic acid manufacturing. Successfully eradicating lactic acid from the physique requires correct functioning of the organs.
If in case you have been recognized with kidney or liver points
Your liver and your kidneys each play a important function in clearing metformin out of your physique. If in case you have extreme kidney or liver illness, you shouldn’t take metformin.
That stated, current tips have change into extra permissive relative to kidney illness, recognizing that metformin could be protected to be used in individuals with gentle to average continual kidney illness (CKD) beneath sure situations.
If in case you have gentle to average CKD, communicate along with your physician about whether or not metformin use is protected in your state of affairs.
If in case you have had a coronary heart assault or acute coronary heart failure
Critical coronary heart situations can have an effect on how a lot blood is pumped to your kidneys, which might cut back your general kidney operate.
As a result of the kidneys play a vital function in clearing metformin out of your physique, individuals with a historical past of coronary heart points shouldn’t take metformin.
If you’ll be having surgical procedure or an imaging check
Lack of fluid and meals previous to surgical procedure can improve the burden on the kidneys and lift the chance of hypertension. And the distinction dyes utilized in sure imaging checks comparable to MRIs can work together with metformin and trigger a drop in kidney operate.
Converse along with your physician about methods to deal with your metformin routine if you’ll be having one in all these procedures.
If you happen to drink alcohol usually or in massive portions
On condition that metformin’s effectiveness is determined by wholesome liver and kidney operate, common heavy alcohol consumption can heighten the chance of issues when taking metformin.
Learn extra: Metformin & Alcohol: Can You Drink Whereas Taking Metformin?
Last ideas
Whereas metformin is mostly nicely tolerated, it might have unintended effects similar to any remedy.
The most typical unintended effects are gentle and gastrointestinal in nature, however extra critical unintended effects comparable to vitamin B12 deficiency and lactic acidosis can happen.
If you happen to expertise any signs whereas taking metformin, discuss to your physician about adjusting your dose, switching to extended-release tablets, or attempting a unique remedy.
If you happen to expertise any critical or life-threatening signs, search medical consideration instantly.
