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Metformin Hydrochloride 500mg Tablets
(Metformin Hydrochloride)
Please read this entire leaflet carefully before you start taking this medicine.
Keep this leaflet. You may need to read it again.
If you have further questions, please ask your doctor or your pharmacist.
This medicine has been prescribed for you personally and you should not pass it on to others. It may
harm them, even if their symptoms are the same as yours.
If any of the side effects get serious or you notice any side effects not listed in this leaflet, please tell your
doctor or pharmacist.
The name of this medicine is Metformin Hydrochloride 500mg Tablets (also referred to as Metformin Tablets
or Metformin, throughout this leaflet)

In this leaflet:


What this medicine is and what it is used for
Before you take
How to take


major surgery, you must tell your doctor. You will
need to stop taking Metformin for a certain period
of time before and after the diagnostic tests or

What this medicine is and what it
is used for

Metformin is an anti−diabetic drug which belongs to a
group of medicines called biguanides. It works by
lowering your blood−sugar level.

Monitoring kidney function and diabetes
Kidney function: As Metformin is excreted by the
kidney your doctor will test your kidney function.
This should be done before starting treatment
and regularly thereafter: once a year for normal
kidney function and two to four times a year if
you have kidney problems or you are elderly
Diabetes: Usual laboratory tests for diabetes
monitoring should be performed regularly

Metformin is used to treat non−insulin dependent
diabetes when a change of diet has failed to reduce
blood sugar levels, particularly if over weight.
It may be used alone as initial therapy or along with
another group of medicines called sulphonylureas,
which stimulate the pancreas to produce more insulin.
Sometimes Metformin Tablets are also used to treat
patients suffering from insulin dependent diabetes,
who are over weight (obese) and whose symptoms
are poorly controlled.
If your blood sugar levels are not controlled, it can lead
to serious problems such as kidney damage, amputations
and blindness. Metformin is thought to work by decreasing
the amount of sugar absorbed from food through the
stomach, by helping the body respond better to the
insulin it makes naturally and by decreasing the
amount of sugar produced by the liver and kidneys.


Before you take

Do not take Metformin Tablets if:
you are allergic to metformin or any of the other
ingredients in these tablets
you have any kind of kidney or liver disease
you have heart failure or have recently had a
heart attack
you suffer from alcoholism
you suffer from a loss or lack of water in the body
you have very high blood sugar levels
(hyperglycaemia) or ketoacidosis, which can lead
to diabetic pre−coma. Ketoacidosis is a condition
in which substances called ’ketone bodies’
accumulate in the blood. Symptoms include
stomach pain, fast and deep breathing,
sleepiness or unusual fruity odour of the breath
you have a severe infection or injury
you suffer from low oxygen levels in your blood
you have or have had a build up of lactic acid in
the blood (lactic acidosis), which may be associated
with shock and breathing difficulties (see Section 2,
’Take special care’ and section 4 ’Possible side
Take special care with Metformin Tablets
if you have diabetes and kidney problems as you
are more at risk of developing a rare but serious
side effect known as ’lactic acidosis’. The risk of
lactic acidosis is also increased with uncontrolled
diabetes, an increased level of ketones in your
blood (ketosis), prolonged fasting, drinking an
excessive amount of alcohol or liver problems
(see section 4 ’Possible side effects’)
if you have kidney problems, particularly if you
are elderly
if you suffer from an upset stomach
if you continuously use Metformin. It may reduce
your vitamin B12 level and should be annually
monitored by your doctor
if you are taking Metformin together with other
medicines used to treat diabetes, such as insulin,
sulphonylureas or meglitinides
if you are to undergo diagnostic tests (using
iodinated contrast media) or you need to have

Possible side effects
How to store
Further information

If any of the conditions listed above under ’Do not
take’ or ’Take special care’ apply to you, please
contact your doctor or pharmacist.
Taking other medicines
Please inform your doctor or pharmacist if you are
taking or have recently taken any other medicines,
including medicines obtained without prescription.
Other medicines may interfere with the actions of your
Metformin Tablets. You should tell your doctor if you
are taking any of the following:
medicines for diabetes such as glibenclamide
(known as sulphonylureas), meglitinides or
medicines called ’diuretics’ that are used to treat
fluid retention or high blood pressure such as
medicines to thin the blood such as warfarin
cimetidine, for stomach ulcers and indigestion.
medicines for inflammation and allergic reactions,
such as betamethasone (glucocortcoids)
Taking with alcohol
You should not drink alcohol whilst taking Metformin.
Alcohol may increase the risk of lactic acidosis
especially if you have liver problems, you are
undernourished or you are fasting.
Pregnancy and breast−feeding
Tell your doctor if you are pregnant, think you may be
pregnant or you are planning to become pregnant as
you should not take Metformin. However, your
diabetes needs to be controlled during pregnancy and
this should be done by taking insulin.
You should not take Metformin whilst breast−feeding
unless your doctor thinks the benefits outweigh the
Ask your doctor or pharmacist for advice before taking
any medicine.
Driving or operating machines
If you are taking Metformin on its own it should not
affect your ability to drive or operate machinery.
However, if you are taking Metformin together with
other medicines to treat diabetes (such as
sulphonylureas, insulin or meglitinides) it may cause
hypoglycaemia (low blood glucose level). Symptoms
of hypoglycaemia include weakness, dizziness,
increased sweating, fast heart beat, vision disorders or
difficulty in concentrating. If you have any of these
symptoms do not drive or use machinery.


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How to take

You should always take this medicine as
prescribed by your doctor. Do not take more than
the doctor told you to. Read and follow the
instructions on the pharmacist’s label. If you are
not sure about anything please ask your doctor or
Metformin Tablets are for oral use only
Recommended to be taken with meals
Normal starting doses
The doses stated below are guidelines only. You
should always take this medicine as prescribed by
your doctor.
The normal dose is 500mg to 2000mg daily in divided
doses. The maximum dose is 3000mg.

Very rare side effects (affects less than 1 in 10,000
skin reactions such as flushing of the skin, itching
or itchy rash
decreased vitamin B12 absorption
abnormal liver function test (detected through
blood test) or inflammation of the liver (hepatitis),
which may cause tiredness, loss of appetite,
weight loss or yellowing of the skin or whites of the
There are only isolated reports of abnormal
liver function or hepatitis and these have been
resolved when treatment was stopped
If any of these side effects get serious or you
notice any not listed, please tell your doctor or


How to store

Your doctor may gradually increase your initial dose, if
it is necessary to control your diabetes.

Keep out of reach and sight of children.
Store below 25°C, protected from light.
Store in the original package.

Elderly patients and patients with kidney problems
Your doctor will choose the correct dosage depending
on the seriousness of your kidney problem.

Do not take after the expiry date , which is stated on
the carton after EXP. The expiry date refers to the last
day of that month.

Metformin Tablets should not normally be given to

If your doctor tells you to stop taking your medicine
you should return any remaining tablets to the
pharmacist, unless your doctor tells you to keep them
at home.

If you forget to take Metformin Tablets at the right
time, take them as soon as you remember. Do not take
a double dose to make up for forgotten individual
If you have taken more Metformin Tablets than you
should, consult your doctor or the nearest hospital
casualty department immediately. Take this leaflet or
some tablets with you so that people will know what
you have taken.
An overdose of Metformin may lead to lactic acidosis
(for symptoms see Section 4 ’Possible side effects’)


Possible side effects

Metformin Tablets are usually well tolerated. However,
like most medicines they can cause unwanted side
effects in some patients.
Serious side effect
Although very rare, some people have developed a
condition known as lactic acidosis whilst taking
Metformin Tablets. Although lactic acidosis is a serious
condition, it is not normally a problem with metformin,
provided it is correctly treated.
Lactic acidosis is caused by a build up of lactic acid in
the blood (produced when glucose is turned into
energy without oxygen).
Possible symptoms of lactic acidosis:
unexplained weight loss
feeling sick (nausea
being sick (vomiting)
general feeling of being unwell
pain in the belly region
difficulty breathing
muscle cramp
severe weakness or loss of strength
feeling cold


Further information

What Metformin Tablets contain:
Active substance: Metformin Hydrochloride.
Each tablet contains 500mg of Metformin
Other ingredients: povidone K30,
microcrystalline cellulose, colloidal anhydrous
silica, magnesium stearate, sodium starch
glycollate, ethyl cellulose 7 cps, hypromellose,
propylene glycol and titanium dioxide (E171).
What Metformin Tablets look like and the
contents of the pack:
Metformin Tablets are round, white, film−coated
They are available in pack size of 28 tablets.
This medicine is only for YOU. Only a doctor can
prescribe it, so never offer it to anybody else. It may
harm them, even if their symptoms seem to be the
same as yours.
Marketing Authorisation Holder & Manufacturer
Tillomed Laboratories Ltd
3 Howard Road,
Eaton Socon, St Neots
PE19 8ET,
Product Licence Number:
PL 11311/0196: Metformin Hydrochloride 500mg

If you have or think you may have lactic acidosis,
you should go to the hospital immediately as it is a
medical emergency.
Very common side effects (affects more than 1 in 10
feeling sick (nausea)
being sick (vomiting)
weight loss
abdominal pain
loss of appetite

Date of last revision: January 2014

These side effects usually occur at the start of
treatment. You should continue to take your medicine
as they normally disappear after a short time. They
may be avoided by taking your medicine with or after
food and in 2 or 3 divided doses.
Common side effects (affects more than 1 in 100
change in taste

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Product Name
Strength / Form
Rev #
Last updated
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Metformin Hydrochloride
500mg Tablets
175 x 380 mm
Font SansSerif − Min. Text 8pt
Pantone Black CVC

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Source: Medicines and Healthcare Products Regulatory Agency

Disclaimer: Every effort has been made to ensure that the information provided here is accurate, up-to-date and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. This information has been compiled for use by healthcare practitioners and consumers in the United States. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate that the drug or combination is safe, effective or appropriate for any given patient. If you have questions about the substances you are taking, check with your doctor, nurse or pharmacist.