Millions of people all over the world use metformin. What does it do? What are the advantages and disadvantages of taking this drug?
Metformin is an oral medication, that is a medicine that you take by mouth. It is used to lower blood sugar, particularly in type 2 diabetes. The generic name is metformin but you may know it better by the brand name of Glucophage.
How does it work?
It works in three ways:
- In the intestines it reduces the absorption of sugar from the food that you eat.
- It stops the liver from breaking down glycogen into glucose and releasing this into the blood.
- It makes your body more sensitive to insulin.
All these work together to bring down your blood sugar.
When do you use metformin?
It is used in several conditions:
- To treat prediabetes,
- To treat type 2 diabetes,
- In type 1 diabetics to make injected insulin more effective.
- It is also sometimes used in PCOS as well as in infertility.
In type I diabetes the body does not produce insulin in the pancreas. Insulin is a hormone that triggers cells to take up sugar out of the blood. Seeing as the body is not making insulin, type I diabetics have to inject insulin.
Type 2 diabetics have very high insulin, especially in the early stages of the disease.
There is a difference when you’re using metformin in type 1 compared to type 2 diabetes. In type 1, you’re taking it to make the body more sensitive to the insulin you are injecting. In type 2 diabetes, you’re using it to make the cells more sensitive to the insulin that your body is already producing.
How do you take it?
Metformin comes in 500 mg, 850 mg, and 1000 mg tablets. You can take it up to 3 times a day. The maximum dose is about 2500 mg a day. However, this may vary according to the formulation that you are using. It is also available in an extended-release form which you would usually take this only once a day.
It is often combined with other diabetes drugs to enhance their effects.
What should you monitor while you’re taking metformin?
- Fasting blood sugar/fasting blood glucose
- HbA1c gives a picture of what your average blood sugar has been over the previous three months.
- Kidney function is important because metformin should not be used in severe kidney disease.
- Complete blood count may show signs of anaemia.
- Vitamin B12 and folic acid levels – long-term use of metformin can lead to a deficiency of vitamin B12 and folic acid, which can also be detected in the complete blood count if it is severe enough.
Advantages of metformin
- It is affordable.
- It is available all over the world.
- It’s an oral drug. There is no need for needles and other things that go with injecting medication.
- It does not cause weight gain which other diabetic medications may cause. On the contrary, many people lose a little bit of weight when they start taking metformin.
- It is not likely to cause hypoglycaemia which is common with other diabetes drugs.
Disadvantages of using metformin
Ithas some serious side effects. These may be so bad that some people stop taking it altogether.
- If you have severe kidney disease you should not use metformin.
- You must limit your alcohol intake to avoid dangerous side effects.
- While the regular version is very affordable, the extended-release version is quite expensive.
Interactions of metformin
There are some drugs that you have to use with care when you’re taking metformin.
The most common ones include:
- Beta-blockers-These are used to treat high blood pressure and other problems of the heart and blood vessels. One example is propranolol. They may cause a lowering of blood sugar which can be dangerous. This is even worse when you combine it with the loweringof the blood sugar that metformin causes.
- Cimetidine – this is used to treat peptic ulcers. Taking cimetidine can increase the amount of metformin in the system.
- Cephalexin – this is an antibiotic that can increase metformin levels
- Quinolone antibiotics – these includes drugs like ciprofloxacin. These can cause an increase in blood sugar.
If you need these drugs to treat related medical problems while taking metformin you can still take them. However to your healthcare provider would be aware of the possible interactions and would need to monitor you very closely.
Metformin side effects
Metformin is a drug used by millions of people all over the world. It is the first-line drug in treating type 2 diabetes which is now at epidemic levels worldwide. And yet, many people are placed on this drug without any formal guidance or advice. Get ready to learn everything you need to know about metformin, its side effects and how you can avoid them.
All drugs have side effects, without exception. When a doctor prescribes any form of medication, she weighs the benefits of that drug against the potential side effects.
For example, daily aspirin tablets are often prescribed for people with heart disease even though they can cause bleeding. So you would need to weigh the benefits of aspirin in preventing blood clots against the risk of uncontrolled bleeding. If the benefits are more than the risks, you go ahead and use the drug. If the risks appear to be higher than the potential benefits, you need to find an alternative.
Metformin has many side effects. Some of these are very common, while others are rare.
Commonest metformin side effects
These include general side-effects like:
- weakness
- dizziness which may lead to falls
- low blood sugar-especially if metformin is used together with insulin
- muscle pain
- chills
- lactic acidosis
- low vitamin B12 levels
- lowered folic acid levels
- low calcium levels
Gastrointestinal side effects
These include:
- unusual taste in the mouth,
- loss of appetite,
- gas,
- diarrhoea,
- abdominal pain,
- nausea,
- vomiting,
- bloating with abdominal distension
- heartburn and
- constipation.
Respiratory side effects
- Chest pain
- upper respiratory tract infection
- persistent cough
Out of these side-effects, the most common are:
- weakness
- dizziness
- gastrointestinal side effects like nausea and vomitin
Virtually any drug that you take by mouth has the potential to cause problems in the stomach and intestines. As usual, side effects vary from one person to another. Just because there are so many adverse effects, it doesn’t mean that you will have all of them. You may not have any at all. In some people, the side effects are so severe that they have to stop taking metformin altogether.
How do you avoid the side effects of metformin?
The best way to avoid metformin side effects is to ease into taking it. You should start on 500 mg once a day, preferably at night (so you can see through any discomfort you may experience).
You should take this for a week or two. If you’re not experiencing huge problems, then you can start taking 500 mg in the morning. Then you can add 500 mg in the evening for another week or two. If you need more metformin to control your blood sugar, then you can add 500 mg every one or two weeks. You can do this until you reach the maximum recommended dosage.
Another option for reducing the side effects of metformin is to use a different form of metformin. Once you’ve swallowed it, the regular metformin starts being released immediately into the stomach. There is another form of metformin known as extended-release metformin. With this preparation, metformin is released gradually throughout the day. It minimises the side effects, especially the gastrointestinal ones. Usually, you would take this once a day in the evening.
A simple way to avoid metformin side effects is never to take metformin on an empty stomach. Wait for about 15 minutes after you eat, then take the metformin. That will make a huge difference, especially in preventing gastrointestinal side effects like nausea, vomiting, heartburn et cetera.
Metformin decreases the absorption of vitamin B12 and folate from the intestines, which can lead to anaemia. Supplementing with vitamin B12 and folic acid helps with this complication.
Lactic acidosis
A rare, but life-threatening side effect of metformin is a condition known as lactic acidosis, which can lead to death.
symptoms and signs of lactic acidosis
these include:
- abdominal pain
- nausea, vomiting and diarrhoea
- fatigue
- muscle pain
- altered mental state
- shallow breathing
Who is at risk of developing lactic acidosis?
- the elderly
- using high dose of metformin
- If you have decreased kidney function, this increases the risk.
- dehydration
- If you’re actively taking alcohol while taking metformin, this will increase your chances of developing lactic acidosis.Infection can increase your chances of developing lactic acidosis while you are taking metformin.
Lactic acidosis is a medical emergency that requires immediate medical attention.
Metformin, x-rays and CT scans
Another area where you need to be careful with metformin is when you’re doing some types of radiological tests. Some x-rays and CT scans may require the injection of iodine-containing contrast medium to help highlight particular areas of the body.
If you have decreased kidney function (with an estimated GFR of less than 30 ml per minute), you need to stop taking metformin before doing the test. Remember that this problem with metformin also applies to drug combinations that include metformin.
The combination of decreased kidney function and the contrast medium used to do the test plus the metformin greatly increases the risk of lactic acidosis.
After 48 hours, if the doctor has assessed your kidney function and found it to be okay, then you would be able to start the metformin again.
I’ve talked about the fact that many people all over the world take metformin to bring down their blood sugar in type II diabetes. It has lots of side effects, the commonest ones being the gastrointestinal side effects. Also, remember that you can greatly reduce the side effects of metformin by starting with the lowest dose possible. You can increase the dosage gradually. Remember to take metformin with meals.
Have you taken metformin before? Did you have any side effects? If you did, how bad were they? Let me know in the comments.