Metformin is without doubt 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 typically properly tolerated, like all medicines, it will probably have unwanted side effects.
On this article, we’ll take a look at how metformin works; its frequent, unusual, and critical unwanted side effects; and the right way to alleviate these unwanted side effects.
Key Factors:
- Frequent unwanted side effects embrace gastrointestinal points comparable to diarrhea, flatulence, and nausea. Some individuals may additionally 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 watch for these situations carefully.
- Unwanted effects will 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 rising 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.
Frequent unwanted side effects of metformin
The commonest unwanted side effects of metformin embrace:
- Diarrhea (various from delicate 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 frequent aspect impact of metformin is weight reduction. Though the medication just isn’t FDA-approved for this use, it’s ceaselessly prescribed off-label for this objective. Within the Diabetes Prevention Program (DPP) Examine, common weight reduction amongst metformin customers was roughly 4.4 to six.6 kilos over two to a few years.
Unusual (critical) unwanted side effects of metformin
Vitamin B12 deficiency
Latest analysis has proven that long-term use of metformin may end up in 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 may cause important nerve injury, in the end resulting in a prognosis of peripheral neuropathy.
If a health care provider isn’t conscious of this danger, they might misdiagnose the reason for an individual’s neuropathy as being the results of excessive blood sugar ranges when it might in truth be a aspect impact of the B12 deficiency attributable to metformin.
This nerve injury is irreversible, however additional injury will be prevented by supplementing with a daily 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 beneficial in some instances.)
Lactic acidosis
There have been a major variety of research on metformin’s danger of inflicting lactic acidosis — a probably deadly situation wherein 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 danger, essentially the most extreme warning that the U.S. Meals and Drug Administration (FDA) points.
That mentioned, in line with “The Phantom of Lactic Acidosis because of Metformin in Sufferers With Diabetes,” printed within the American Diabetes Affiliation’s (ADA) journal Diabetes Care, the overwhelming majority of research discovered no cases 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 will 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, notably in younger individuals with out danger components, counsel that metformin may cause lactic acidosis primarily if given in giant doses.”
These most susceptible 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 enhance insulin manufacturing like many different diabetes medicines.
Name your physician you probably have any signs of hypoglycemia, which may embrace:
- Weak point
- Tiredness
- Nausea
- Vomiting
- Abdomen ache
- Dizziness
- Lightheadedness
- Abnormally quick or sluggish heartbeat
“Faux” low blood sugar
Whereas this isn’t a destructive aspect impact, it’s an necessary state of affairs to concentrate on when beginning on metformin.
Whenever you drop your blood sugars to a “regular” vary after operating persistently excessive for some time, it’s possible you’ll expertise “faux” signs of low blood sugar.
As a result of your physique has turn out to be used to excessive blood sugars, returning to regular ranges could make you’re feeling dizzy, lightheaded, nauseous, and intensely hungry.
This could cross after a number of days to weeks as your physique adjusts to your new regular blood sugar ranges.
When you’re feeling low, all the time test your blood sugar to be sure you aren’t experiencing an actual low blood sugar (sometimes thought-about 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
When you expertise any of those signs, search medical consideration instantly.
How lengthy after taking metformin do unwanted side effects begin?
Metformin’s unwanted side effects normally seem rapidly after the primary dose, and whereas they enhance for some individuals after a number of weeks, others could discover they persist.
Others could not even start to expertise unwanted side effects till they’ve been taking the drug for months or a 12 months.
Lowering metformin unwanted side effects
Thankfully, there are some things you are able to do to alleviate, reduce, or altogether forestall the unwanted side effects attributable to metformin.
Take your dose throughout your meal, not earlier than
One key step is to take your metformin dose midway by way of consuming your meal, fairly than earlier than you begin consuming.
Individuals taking the medication report far much less abdomen misery if there may be already meals of their abdomen by the point their metformin dose is being digested.
Begin with a really small dose
By beginning with a particularly small dose, as a substitute of the total dose your physician would usually prescribe to your top and weight, you could possibly drastically scale back these initially uncomfortable unwanted side effects.
If that is an strategy you’d prefer to strive, discuss to your physician about adjusting your doses with a purpose 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 typically, 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 unwanted side effects of metformin.
Nonetheless, it’s possible you’ll must strive 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 will be important to not crush, break, or chew your metformin tablets, as doing so might trigger them to be absorbed extra rapidly and enhance the danger of unwanted side effects.
Mix it with different diabetes medicines
In case your healthcare supplier intends to begin you on a GLP-1 drug, the unwanted side effects of metformin can really assist counterbalance the constipating unwanted side effects of most of the medicines on this class.
GLP-1 medicines for diabetes presently out there in america embrace the next:
- Dulaglutide (model title Trulicity)
- Exenatide (Byetta)
- Exenatide prolonged launch (Bydureon bcise)
- Liraglutide (Victoza, Saxenda)
- Lixisenatide (Adlyxin)
- Semaglutide (Ozempic, Rybelsus)
By together with each varieties of medication in your diabetes administration plan, the unwanted side effects could assist primarily steadiness one another out.
Learn extra: Metformin Mixture Medication for Kind 2 Diabetes
Strive one thing else
There are some individuals who merely don’t tolerate metformin. When you discover you can not bear the unwanted side effects, discuss to your healthcare workforce.
When you select to cease taking metformin, they might help you discover a completely different kind of diabetes remedy to handle your blood sugar ranges.
Learn extra: The Finest Alternate options to Metformin for Kind 2 Diabetes Administration
Meals to keep away from to attenuate unwanted side effects
Consultants don’t particularly advocate avoiding any explicit meals whereas taking metformin to stop gastrointestinal unwanted side effects comparable to diarrhea.
That mentioned, there are specific meals and drinks that may enhance the danger of those points on the whole, so it’s possible you’ll need to scale back your consumption of them if you’re 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 will 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 adjustments 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 danger of extreme lactic acid manufacturing. Successfully eradicating lactic acid from the physique requires correct functioning of the organs.
When you have been identified with kidney or liver points
Your liver and your kidneys each play a crucial position in clearing metformin out of your physique. When you have extreme kidney or liver illness, you shouldn’t take metformin.
That mentioned, current tips have turn out to be extra permissive relative to kidney illness, recognizing that metformin will be secure to be used in individuals with delicate to average persistent kidney illness (CKD) below sure situations.
When you have delicate to average CKD, communicate together with your physician about whether or not metformin use is secure in your state of affairs.
When you have had a coronary heart assault or acute coronary heart failure
Severe coronary heart situations can have an effect on how a lot blood is pumped to your kidneys, which may scale back your total kidney operate.
As a result of the kidneys play an important position in clearing metformin out of your physique, individuals with a historical past of coronary heart points shouldn’t take metformin.
If you may be having surgical procedure or an imaging check
Lack of fluid and meals previous to surgical procedure can enhance the burden on the kidneys and lift the danger of hypertension. And the distinction dyes utilized in sure imaging assessments comparable to MRIs can work together with metformin and trigger a drop in kidney operate.
Converse together with your physician about the right way to deal with your metformin routine if you may be having considered one of these procedures.
When you drink alcohol typically or in giant portions
On condition that metformin’s effectiveness relies on wholesome liver and kidney operate, common heavy alcohol consumption can heighten the danger of problems when taking metformin.
Learn extra: Metformin & Alcohol: Can You Drink Whereas Taking Metformin?
Last ideas
Whereas metformin is usually properly tolerated, it will probably have unwanted side effects similar to any remedy.
The commonest unwanted side effects are delicate and gastrointestinal in nature, however extra critical unwanted side effects comparable to vitamin B12 deficiency and lactic acidosis can happen.
When you expertise any signs whereas taking metformin, discuss to your physician about adjusting your dose, switching to extended-release tablets, or attempting a distinct remedy.
When you expertise any critical or life-threatening signs, search medical consideration instantly.
