Metformin is likely one of the most prescribed medicines on the planet, with greater than 150 million individuals at present taking it for kind 2 diabetes administration (and, in some instances, weight reduction).
Whereas it’s usually effectively tolerated, like all drugs, it could have unwanted effects.
On this article, we’ll have a look at how metformin works; its widespread, unusual, and critical unwanted effects; and tips on how to alleviate these unwanted effects.
How metformin works
Metformin (model names Glucophage, Glucophage XR, Fortamet, Glumetza, and Riomet, plus varied generics) works by lowering 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 unwanted effects of metformin
The most typical unwanted effects of metformin embrace:
- Diarrhea (various from delicate to extreme)
- Flatulence (passing fuel)
- 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 aspect impact of metformin is weight reduction. Though the drugs just isn’t FDA-approved for this use, it’s regularly prescribed off-label for this function. Within the Diabetes Prevention Program (DPP) Research, common weight reduction amongst metformin customers was roughly 4.4 to six.6 kilos over two to a few years.
See extra in: Metformin and Weight Loss: Can a Capsule Assist You Lose Weight?
Meals to keep away from whereas taking metformin
Consultants don’t particularly suggest avoiding any explicit meals whereas taking metformin to forestall gastrointestinal unwanted effects comparable to diarrhea.
That stated, there are specific meals and drinks that may improve the chance of those points typically, so chances are you’ll wish to cut 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 (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols — sure sugars which can be 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 adjustments may assist handle gastrointestinal signs comparable to diarrhea whereas taking metformin.
Study extra in: Can Metformin Trigger Diarrhea? and Meals to Keep away from Whereas Taking Metformin.
How lengthy after taking metformin do unwanted effects begin?
Metformin’s unwanted effects often 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 effects till they’ve been taking the drug for months or a yr.
Unusual (critical) unwanted 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 may cause important nerve injury, in the end resulting in a prognosis of peripheral neuropathy.
If a physician 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 could actually be a aspect impact of the B12 deficiency brought on by metformin.
This nerve injury is irreversible, however additional injury might 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 useful in some instances.)
Lactic acidosis
There have been a big variety of research on metformin’s danger of inflicting lactic acidosis — a probably deadly situation during which lactic acid builds up within the physique. Signs of lactic acidosis can embrace:
- Nausea
- Vomiting
- Weak spot
- Fatigue
- Quick, deep respiration
- Muscle cramps and physique aches
Metformin comes with a “black field” warning about this danger, probably the most extreme warning that the U.S. Meals and Drug Administration (FDA) points.
That stated, a large-scale research reported in 2022 examined 4,241 instances of suspected metformin-associated lactic acidosis and located that solely a small fraction (9 p.c) had ample information to help such a prognosis, underscoring the rarity of this situation.
Virtually all instances of lactic acidosis from metformin use are outcomes of overdoses — not regular use of the drug.
These most prone to creating lactic acidosis whereas on metformin embrace individuals with circumstances comparable to kidney or liver points, a historical past of coronary heart assaults or acute coronary heart failure, and frequent alcohol customers.
See extra in: Can Metformin Trigger Lactic Acidosis?
Hypoglycemia (low blood sugar)
Metformin solely very hardly ever 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 drugs.
Name your physician if in case you have any signs of hypoglycemia, which might embrace:
- Weak spot
- Tiredness
- Nausea
- Vomiting
- Abdomen ache
- Dizziness
- Lightheadedness
- Abnormally quick or sluggish heartbeat
“Faux” low blood sugar
Whereas this isn’t a unfavorable aspect impact, it’s an vital scenario to concentrate on when beginning on metformin.
Whenever you drop your blood sugars to a “regular” vary after operating persistently excessive for some time, chances are 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 are feeling dizzy, lightheaded, nauseous, and very hungry.
This could move 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 of to be under 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
- Issue respiration
When you expertise any of those signs, search medical consideration instantly.
Lowering metformin unwanted effects
Fortuitously, there are some things you are able to do to alleviate, reduce, or altogether stop the unwanted effects brought on by metformin.
Take your dose throughout your meal, not earlier than
One key step is to take your metformin dose midway by means of consuming your meal, slightly than earlier than you begin consuming.
Individuals taking the drugs 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 an especially small dose, as an alternative of the complete dose your physician would usually prescribe in your peak and weight, you might be able to drastically cut back these initially uncomfortable unwanted effects.
If that is an method you’d wish to strive, speak to your physician about adjusting your doses as a way to give your physique time to acclimate to the drug.
Learn extra in: Metformin Dosage Information (Min and Max Doses).
Ask for the “extended-release” model
Too usually, medical doctors 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 progressively launched over a number of hours as an alternative of instantly. This course of successfully lessens the undesirable gastrointestinal signs.
Though it could be costlier, this method can considerably lower the general unwanted effects of metformin.
Nevertheless, chances are 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 suitable remedy for you. Then they are going to be extra prone to cowl the extended-release model.
Take your dose entire
It is crucial to not crush, break, or chew your metformin tablets, as doing so may trigger them to be absorbed extra rapidly and improve the chance of unwanted effects.
Mix it with different diabetes drugs
In case your healthcare supplier intends to begin you on a GLP-1 drug, the unwanted effects of metformin can really assist counterbalance the constipating unwanted effects of most of the medicines on this class.
GLP-1 drugs for diabetes at present out there 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 medicine in your diabetes administration plan, the unwanted effects could assist primarily stability one another out.
Learn extra in: Metformin Mixture Medicine for Kind 2 Diabetes.
Attempt one thing else
There are some individuals who merely don’t tolerate metformin. When you discover you can’t bear the unwanted effects, speak to your healthcare workforce.
When you select to cease taking metformin, they may also help you discover a totally different kind of diabetes remedy to handle your blood sugar ranges.
Learn extra in: Stopping Metformin: When and How You Can Cease Taking Metformin and The Finest Options to Metformin for Kind 2 Diabetes Administration.
Who ought to keep away from taking metformin?
As with all drugs, 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 crucial 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, latest tips have turn out to be extra permissive relative to kidney illness, recognizing that metformin might be secure to be used in individuals with delicate to reasonable power kidney illness (CKD) below sure circumstances.
If in case you have delicate to reasonable CKD, communicate together with your physician about whether or not metformin use is secure in your scenario.
If in case you have had a coronary heart assault or acute coronary heart failure:
Critical coronary heart circumstances can have an effect on how a lot blood is pumped to your kidneys, which might cut back your general kidney perform.
As a result of the kidneys play an important function in clearing metformin out of your physique, individuals with a historical past of coronary heart points mustn’t take metformin.
When you drink alcohol usually or in massive portions:
On condition that metformin’s effectiveness is determined by wholesome liver and kidney perform, common heavy alcohol consumption can heighten the chance of issues when taking metformin.
Learn extra: Metformin & Alcohol: Can You Drink Whereas Taking Metformin?
If you may 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 perform.
Communicate together with your physician about tips on how to deal with your metformin routine if you may be having certainly one of these procedures.
Study extra in: Is Metformin Protected?
Last ideas
Whereas metformin is usually effectively tolerated, it could have unwanted effects similar to any remedy.
The most typical unwanted effects are delicate and gastrointestinal in nature, however extra critical unwanted effects comparable to vitamin B12 deficiency and lactic acidosis can happen.
When you expertise any signs whereas taking metformin, speak 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.
Recommended subsequent article: Every part You Must Know About Metformin.
